WO2005091892A2 - System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components - Google Patents

System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components Download PDF

Info

Publication number
WO2005091892A2
WO2005091892A2 PCT/US2005/006305 US2005006305W WO2005091892A2 WO 2005091892 A2 WO2005091892 A2 WO 2005091892A2 US 2005006305 W US2005006305 W US 2005006305W WO 2005091892 A2 WO2005091892 A2 WO 2005091892A2
Authority
WO
WIPO (PCT)
Prior art keywords
manifold
inlets
components
valves
fluid
Prior art date
Application number
PCT/US2005/006305
Other languages
French (fr)
Other versions
WO2005091892A3 (en
Inventor
Darwin G. Enicks
Carl E. Friedrichs
Richard A. Brucher
Original Assignee
Atmel Corporation
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Atmel Corporation filed Critical Atmel Corporation
Priority to EP20050723954 priority Critical patent/EP1784595A2/en
Publication of WO2005091892A2 publication Critical patent/WO2005091892A2/en
Publication of WO2005091892A3 publication Critical patent/WO2005091892A3/en

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16KVALVES; TAPS; COCKS; ACTUATING-FLOATS; DEVICES FOR VENTING OR AERATING
    • F16K27/00Construction of housing; Use of materials therefor
    • F16K27/003Housing formed from a plurality of the same valve elements
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/0318Processes
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/4238With cleaner, lubrication added to fluid or liquid sealing at valve interface
    • Y10T137/4245Cleaning or steam sterilizing
    • Y10T137/4259With separate material addition
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/8593Systems
    • Y10T137/85978With pump
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10TTECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00Fluid handling
    • Y10T137/8593Systems
    • Y10T137/877With flow control means for branched passages
    • Y10T137/87877Single inlet with multiple distinctly valved outlets

Definitions

  • the invention relates to semiconductor device fabrication equipment in general, and, in particular, to a system, apparatus, and method for contaminant reduction of semiconductor device fabrication equipment components.
  • Semiconductor device fabrication equipment components tend to accumulate contaminants, through for example, adsorption and absorption, before, during, and/or after the operation of the fabrication equipment.
  • contaminants include, for example, moisture, oxygen, atmosphere, or any other gases.
  • Possible contaminant sources are process gases as well as the atmosphere.
  • Even components that have been cleaned, by cleaning processes known in the art, or that are new, are subject to accumulation of contaminants.
  • the components of the semiconductor device fabrication equipment become a source of contaminants, in addition to process gases.
  • Contaminants on components are undesirable for at least the reasons that they degrade the quality of the fabricated semiconductor device manufactured and reduce the efficiency of the fabrication process.
  • the method of semiconductor device fabrication involves depositing epitaxially-grown silicon germanium (SiGe) on a silicon substrate in a chemical vapor deposition (CVD) reactor, during SiGe deposition, oxygen present in the CVD reactor is typically incorporated into the SiGe film. Elevated oxygen levels present in the CVD reaction chamber used to deposit SiGe causes numerous problems in the SiGe films produced in the CVD reactor chamber. Among these problems are elevated sheet resistance of the SiGe p-type base and poor crystal, quality.
  • the amount of absorbed or adsorbed contaminants, such as oxygen increases in order to achieve acceptable oxygen levels in SiGe films. While the reactor is offline, it is disassembled to remove contaminants, reassembled, and then tested. The longer the reactor is offline, the less cost effective manufacturing becomes, as an offline reactor cannot be used for manufacturing semiconductor chips. Also, elevated contaminant levels in the reactor components may lead to early reactor failure and a decreased reactor lifetime. Therefore, it is an object of the present invention to provide a system, method, and apparatus for reduction or- elimination of contaminants found in semiconductor device fabrication equipment components. It is another object of the present invention to reduce or: eliminate levels of contaminants on semiconductor device fabrication equipment components.
  • Additional objects of the present invention are to reduce preventative maintenance recovery time, process recovery time, and mean time to repair (MTTR) and to increase mean time between interrupt (MTBI) and mean time between cleans (MTBC) .
  • MTTR preventative maintenance recovery time
  • MTBI mean time between interrupt
  • MTBC mean time between cleans
  • the purge fluid may include a gas selected from a variety of different types of gases, including nitrogen.
  • the purge fluid may be inert.
  • the manifold has a pair of capped ends, a main passageway, a plurality of inlets in fluid communication with the main passageway, manifold valves connected to the plurality of inlets to which semiconductor device fabrication equipment components are connectable, and an exhaust fitting connected to the manifold at a location downstream from the inlet closest to the capped end.
  • one of the capped ends is connected to a fluid source and the exhaust fitting is connected to a pump which pumps fluid introduced into the manifold out of the manifold under vacuum.
  • vacuum as referred to in the description of the present invention, means a low pressure environment .
  • the system and apparatus further include caps which are connectable to the manifold valves and to a type of component to undergo contaminant reduction having a pair of openings.
  • a component having two openings such as a ball valve or a pressure control valve
  • one end of the component is connected to the manifold valve at an end having a first opening and the other end of the component having a second opening is capped with a cap to maintain the vacuum within the manifold by preventing atmospheric particles from entering the component and manifold.
  • the component is a rotation assembly
  • one end of the rotation assembly including an opening is connected to the manifold valve, while the other end is typically already closed and thus does not require a cap.
  • an uncovered manifold valve opening may be capped to maintain the vacuum within the system when the valve is in an open position.
  • Cap valves may be connected to the caps.
  • a vacuum typically exists within the system.
  • the cap valve is opened to slowly let air into the component and to vent the component out to atmosphere.
  • the system includes an oven connected to the pump for outgassing components of semiconductor device fabrication equipment .
  • a purge fluid such as nitrogen gas, is introduced into the manifold. Nitrogen gas, in particular nitrogen gas introduced in a vacuum, assists in the removal of oxygen from surfaces of the components.
  • Components to undergo contaminant reduction are connected to the manifold valves.
  • three sets of components are connected to the manifold valves at the openings.
  • two rotation assemblies, two ball valves, and two pressure control valves are connected to manifold valves of the system.
  • the inlets of the manifold may be facing downwardly for connection to a manifold valve to which a rotation assembly is to be connected, or frontwardly for connection to a manifold valve to which a ball valve or pressure control valve is to be connected.
  • the manifold valves and components may be capped to maintain the vacuum within the system.
  • Fluid is introduced into the main passageway of the manifold and is dispersed to inner surfaces of components via the manifold inlets and connected manifold valves which are in the open position. Fluid is pumped out of tie components, inlets, and manifold valves through the exhaust pipe connected to the pump. While the components are undergoing contaminant reduction, additional components may be disposed within the oven for outgassing. When the components have undergone contaminant reduction, they are removed from the system and are ready for use .
  • the apparatus and system of the present invention is advantageous in at least that it reduces the amount of contaminants, such as oxygen, found on surfaces of semiconductor device fabrication equipment components. A reduction in oxygen within the components will result in an improvement in the quality of semiconductor devices manufactured by the equipment .
  • trie present invention may reduce contaminants of more than one component and more than one type of component at a time. These components may be connected to the manifold valves, found within the oven, or both. Additionally, reduction of contaminants on components, with the system, apparatus, and method of the present invention, makes future removal of contaminants easier to achieve. Therefore, preventative maintenance recovery time, process recovery time, and mean time to repair (MTTR) are reduced. Further, mean time between interrupt (MTBI) of operation and mean time between cleans (MTBC) will increase as the semiconductor fabrication device equipment will not need to be maintained as often if contaminant reduction has been achieved with the present invention.
  • the system and apparatus of the present invention may be utilized in conjunction with semiconductor device fabrication equipment components for several different types of semiconductor processes including, for example, SiGe, EPI, thin film, diffusion, etch, and implant processes .
  • Fig. 1 is a perspective view of the system of the present invention.
  • Fig. 2 is a front view of a portion of the system of Fig. 1.
  • Fig. 3 is a top view of a portion of the system of Fig. 1.
  • Fig. 4 is a perspective view of a frame of the system of Fig. 1.
  • Fig. 5a is a perspective view of a manifold of the system of Fig. 1.
  • Fig. 5b is a front view of the manifold of Fig. 2a.
  • Fig. 5c is a top view of the manifold of Fig. 2b.
  • Fig. 6a is a partial perspective view of the system of Fig. 1.
  • Fig. 6b is an exploded view of Fig. 6a.
  • Fig. 7a is another partial perspective view of the system of Fig. 1.
  • Fig. 7b is an exploded view of Fig. 7a.
  • the system 10 of the present invention is seen featuring a manifold 12.
  • the manifold 12 is, for example, a stainless steel pipe, having a length of, for example, 178cm (70 1/8 inches) .
  • the manifold 12 includes a main internal passageway 14 capped with first and second capped ends 16 and 18 (cap 18 is not shown in Fig.
  • Capped end 16 includes flange 26a and capped end 18 includes flange 26b.
  • flanges 26a and 26b are NW100 flanges.
  • each inlet 22 is approximately 5cm (2 inches) long and has a flange, for example an NW40 flange, that has an opening that is approximately 4cm (1.6 inches) in diameter.
  • the exhaust fitting 24 is approximately 8.9cm (3 1/2 inches) long and has an opening that is approximately 5cm (1.97 inches) in diameter.
  • Fluid source 20 is connected to the opening of the first capped end via fluid supply line 28.
  • a plurality of manifold valves 30a-30g is connected to the manifold inlets 22a- 22g respectively.
  • Manifold valves 30a-30g may be connected to inlets 22a-22g via flange connections, or flange joints, 69a-69g (Figs.
  • Manifold valves have handles 39a-39g (Fig. 1) which are operated to place the manifold 12 and connected components into and out of fluid communication with the inlets 22 and main passageway 14.
  • the manifold valves 30 are, for example, ball valves.
  • Each manifold valve 30 has a first end connected to one of the plurality of inlets 22a-22g and a second end to which a component is removably connected.
  • a pump 32 for example a roughing pump, is connected to the exhaust fitting 24 via a pipe 34.
  • Other pressure reduction means for providing a reduced pressure within the manifold may be used.
  • a pipe valve 36 is operable to place the exhaust fitting 24 into and out of fluid communication with the pipe 34 and pump 32.
  • a primary pump controller 42 for example an EBARA A70W LCD controller (manufactured by Ebara Corp. Fujisawa, Japan) is seen disposed on the pump body 40 as a part of interface box 41. Wheels 44, which assist in transport of the pump 32, are connected to the pump body 40.
  • a secondary pump controller 52 fox example an EBARA A70W LCD controller, is disposed on a top surface 54 of the oven 46. A user may choose to control the pump through the primary or secondary controller.
  • the system includes an oven 46 connected to the pump 32 via pipe 47.
  • the oven 46 is, for example, a vacuum drying and outgas sing oven.
  • One example of the oven is manufactured by Oven Technology Incorporated (Albuquerque, New Mexico) .
  • the oven 46 includes handle 48 for opening oven door 50 to the oven chamber (not shown) .
  • the oven also includes a controller, not shown here.
  • Semiconductor fabrication equipment components such as o-rings and internal chamber components comprising quartz, stainless steel, or silicon carbide (not shown) , are placed within the chamber of the oven for drying and outgassing.
  • exemplary frame 56 further includes pillars 58 and frame elements 60.
  • Frame elements 6,0a-60f are connected via connection elements 62.
  • connection elements are bolts.
  • the frame 56 is, for example steel. Steel such as treated steel, including galvanized steel or Unistrut ® (manufactured by Unistrut, Wayne, MI) may be used. Feet 64, located beneath the pillars 58, assist in distributing the load of the system 10.
  • the manifold 12 is inserted within stirrups 66a- 66d connected to frame elements 60a-60d, respectively.
  • the stirrups 66 support the manifold 12.
  • the frame 56 is 143cm (56 3/8 inches) high, 56cm (22 1/8 inches) wide, and 139cm (54 3/4 inches) long. At the widest point the frame 56 is, for example, 67cm (26 3/16 inches) wide.
  • the stirrups 66 are disposed 29cm ( 11 7/16 inches) from frame element 60e measured from a center print of the stirrup. Other frame dimensions may be used.
  • bracket 68 is utilized to support a flow regulator 70 (Fig.
  • the flow regulator 70 is a TESCOM 64-2600 series regulator (manufactured by Tescom Corp., Elk River, MN) .
  • a column 72 (Fig. 1) is used to support a flow controller 74 which regulates the fluid flow. In one example, the column 72 has a height of approximately 37.5cm (14 3/4 inches) .
  • the fluid source 20 is connected to the flow regulator 70 via supply line 28.
  • the flow regulator 70 is connected to the flow controller 74 via supply line 28 which is, for example, connected in series.
  • the supply line 28 is connected to the opening of the capped end 16.
  • Bracket 76 supports a Mini Convectron ® power supply 78 (manufactured by Granville Phillips, Longmont, CO) .
  • the Mini Convectron Module 80 which measures the pressure of the manifold 12, is disposed on the manifold 12.
  • the manifold inlets 22a-22g are spaced to accommodate various types and sizes of semiconductor device fabrication equipment components.
  • inlets 22a-22g may be spaced apart to allow for connection of different types of components.
  • inlets 22a and 22b are spaced apart by approximately 25.4cm (10 inches) , measured from a center point of each of the inlets.
  • Pairs of inlets for example, inlets 22b and 22c, 22c and 22d, 22d and 22e, 22e and 22f, and 22f and 22g, are spaced apart by, for example, 22.4cm (8 13/16 inches) , measured from a center point of one inlet of each pair of inlets to a center point of the next inlet of the pair. Spacing between a pair of inlets allows for connection of various components to trie respective inlets. With reference to Fig.
  • spacing between inlets 22a and 22b allows for a pair of components, for example, a pair of rotation assemblies 82a and 82b, to be connected to inlets 22a and 22b. Spacing between inlets 22b and 22c allows for a pair of components, for example, rotation assembly 82b and a pressure control valve 84a, to be connected to inlets 22b and 22c, respectively. Spacing between inlets 22c and 22d allows for a pair of components, for example , pressure control valve 84a and a pressure control valve 84b, to be connected to inlets 22c and 22d.
  • Spacing between inlets 22d and 22e allows for a pair of components, for example, pressure control valve 84b and a ball valve control valve 86a, to be connected in inlets 22d and 22e, respectively. Spacing between inlets 22d and 22e allows for a pair of components, for example, ball valve 86a and a ball valve 86b, to be connected to inlets 22d and 22e, respectively. Spacing between inlets 22f and 22g allows for a pair of components to be connected to each inlet, respectively.
  • the example in Fig. 1 depicts pressure control valve 86b connected to inlet 22f and a cap 134e connected to inlet 22g. Instead of the cap, a component could be connected to inlet 22f .
  • the type of component connected to each inlet may vary.
  • the spacing between inlets should be sufficient to accommodate the desired components.
  • Inlets may be downwardly facing, as are inlets 22a and 22b, or frontwardly facing as are inlets 22c-22g.
  • the spacing and orientation of the inlets 22 assists in the accommodation of one or more sets of components.
  • One or more components or various sets of components from semiconductor device fabrication equipment may undergo contaminant reduction at a single time.
  • three sets of components, each set including two components, namely one of a rotation assembly 82, a pressure control valve 84, and a chamber ball valve 86, are connected to the manifold for contaminant reduction.
  • downwardly facing inlets 22a and 22b may be dedicated to rotation assembly attachment.
  • components connected to inlets 22c-22g are interchangeable in position at these inlets.
  • Additional semiconductor device fabrication equipment components having a surface, for example an internal surface, and at least one opening leading to the surface may be connected to the manifold valves to undergo contaminant reduction.
  • the term surface may be used to encompass any surface of the component to undergo contaminant reduction.
  • Inlet 22a is spaced apart from flange 26a by, for example, 11.7cm (4 5/8 inches) from a center point of the inlet.
  • Inlet 22g is spaced apart by, for example, 26.7cm (10 1/2 inches) from the flange 26b, measured from a center point of the inlet.
  • Exhaust fitting 24 is spaced apart by, for example 9.68cm (3 13/16 inches) from flange 26b, measured from a center point of the fitting.
  • Figs. 1-3 six manifold valves 30a-30g are depicted connected to various components.
  • Rotation assemblies 82a and 82b which are depicted in representational form, are connected to manifold valves 30a and 30b, respectively, at an opening of each of the rotation assemblies leading to an internal surface of the rotation assembly.
  • Rotation assemblies 82a and 82b include the same elements and are connected to the manifold 12 in the same manner, thus the elements and the connection will be explained only with regard to one rotation assembly. Referring to Fig.
  • rotation assembly 82a includes a rotation assembly body 96 .
  • Rotation assembly flange 97 is connected to the cup 98. Still referring to Figs.
  • rotation assembly 82a is seen connected to manifold valve 30a via, for example, fitting 120 and ball joint 102.
  • the fitting 120 is connected to the ball joint 102, at one end, and to the manifold valve 30a, at another end, via flange joints 121 and 123, respectively.
  • the fitting 120 is connected to a valve 122 via tubing 124.
  • the ball joint 102 includes a ball joint flange 104 with bolt openings 106, a male connector 108, and flange 110 which is for example, a KF flange.
  • the male connector is inserted, at one end, within opening 83 of rotation assembly cup 98 of rotation assembly 82a.
  • the male connector 108 is inserted through ball joint flange opening 112 and flange 110.
  • Bolts 114 are inserted through openings 106 of the ball joint flange and notches 118 of rotation assembly flange 97 to secure the -ball joint to the rotation assembly cup 98.
  • Other types of connections including other rotatable joints, may be utilized to connect each rotation assembly to one of the manifold valves.
  • pressure control valves 84a and 84b which are depicted in representational form, are connected to manifold 12 via manifold valves 30c and 30d, respectively.
  • Pressure control valve 84a includes the same components as and is connected to manifold 12 in the same manner as pressure control valve 84b, thus the components and connection to the manifold 12 of the chamber -ball valves will be described in detail with regard to one of the pressure control valves only.
  • the components and connection of pressure control valve 84b to manifold 12 is as follows. Pressure control valve 84b is connected to manifold valve 30d at a first opening 88 of the pressure control valve leading to an internal surface 90, seen in Fig. 7b. In addition to first opening 88 , pressure control valve 84b includes a second opening 126 to the interior surface 90.
  • the end of the pressure control valve 84b connected to the manifold valve 30d is proximate the first opening 88 of the pressure control and includes a flange 77.
  • Manifold valve 30d also includes a flange 79 which forms a flange connection or flange joint 155 (Fig. 7a.) with flange 77.
  • the flange connection is, for example, a KF40 flange connection.
  • the second opening 126 of pressure control valve 84b is closed during operation of the system to prevent fluid, such as atmospheric particles, from entering the system and to allow the system to operate under vacuum.
  • cap 134b of cap assembly 135b closes opening 126 ⁇ Fig. 7b) during operation of the system.
  • Cap 134b includes a flange 130, which forms a flange connection 151 (Fi-g. 7a) with a flange 133 located on an end of the pressure control valve 84b proximate the second opening 126, and may comprise a metallic material .
  • Chamber ball valves 86a and 86b which are depicted in representational form, are connected to manifold 12 via manifold valves 30e and 3 Of, respectively (Fig. 1) . With reference to Fig. 7a and Fig. 7b, the connection of chamber ball valve 86a to manifold 12 is depicted in detail.
  • Chamber ball valves 86a and 86b include the same components and are connected to manifold 12 in the same manner, tnus the components and connection to the manifold 12 of the chamber ball valves will be described in detail with regard to one of the chamber ball valves only.
  • the components and connection of chamber ball valve 86a to manifold 12 is as follows. Chamber ball valve 86a is connected to manifold valve 30e at a first opening 92 of the chamber ball valve leading to an internal surface 94, seen in Fig. 7b. In addition to first opening 92, chamber ball valve 86a includes a second opening 128 to the interior surface 94.
  • the end of the chamber ball valve 86a connected to the manifold valve 30e is proximate tre first opening 92 of chamber ball valve 86a and incluc3.es a flange 93.
  • Manifold valve includes a flange 95 whioh forms a flange connection, or flange joint 157 (Fig. 7_a) , with flange 93.
  • the flange connection is, for example, a KF40 flange connection.
  • the second opening 128 of chamber ball valve 86a is closed during operation of the system to prevent fluids from escaping the system and to allow the system to operate under vacuum.
  • cap 134c of cap assembly 135c closes opening 128 during operation of the system.
  • Cap 134c includes a flange 132, which forms a flange connection 153 (Fig. 7a) with a flange 135 located on an end of the chamber ball valve 86a proximate the second opening 128, and may comprise a metallic material.
  • cap assemblies 135a-135e are seen featuring valves, caps, and tubing. Valves 137a-137e are connected to the caps 134a-134e, respectively, via tubing 139a-139e. Gas may be vented to each component through the corresponding valve 137a-137e and via the tubing elements 139a-139e, as will be described below.
  • a cap such as cap 134e, may be used to seal an opening of the manifold valve.
  • a cap is not required to seal an opening of the manifold valve 30g, as the valve 30g may be placed in a closed position by adjustment with handle 39g (Fig. 1) to prevent fluid, such as atmospheric particles, from entering the manifold valve.
  • cap assembly 135e may be removed from manifold valve 30g so that a residual gas analyzer may be connected to manifold valve 30g to analyze gas within the manifold 12.
  • a purge fluid such as nitrogen gas, an inert gas, or another type of gas or other purge substance, is introduced into the manifold 12 for reducing contaminants present on the components .
  • nitrogen gas is advantageous as a purge fluid as it assists in the removal of oxygen from surfaces of the components in the system.
  • nitrogen is contained within the fluid source 20 at, for example, a pressure ranging from approximately 3620 Torr to 5171 Torr (70 psig to 100 psig) .
  • Supply line 28 transports the nitrogen from the nitrogen source 20 to flow regulator 70 which regulates the flow of gas to, for example, approximately 259 Torr + 52 Torr (5+ 1 psig) .
  • the regulated nitrogen gas is transported from the nitrogen regulator 70 to the flow controller 74.
  • the gas is transported to the opening of capped end 16 via supply line 28.
  • Nitrogen is introduced into the main passageway 14 as well as to the connected components via the plurality of inlets 22a-22f and manifold valves 30a-30f .
  • manifold valve 30g lacks a component, but may still be placed in fluid communication with the nitrogen, as described above.
  • Inlets and manifold valves include passageways through which fluid is transported.
  • Inlets 22a-22g include passageways 23a-23g, seen in Figs. 5a-5c.
  • passageways are seen as elements 61, 63, and 65 (Fig. 6b and Fig. 7b) , respectively.
  • the other manifold valves include passageways which are not depicted.
  • the fluid travels along the passageways of the inlets and manifold valves and reaches the internal surfaces of the components.
  • oxygen is removed from the internal surfaces of the components.
  • Fluid, such as oxygen gas, removed from the surfaces, is pumped out of the components 82a, 82b, 84a, 84b, 86a, and 86b, inlets 22a- 22g and manifold valves 30a-30g, through the exhaust pipe 24 connected to the pump 32.
  • the system operates under a vacuum.
  • the manifold pressure is 25 ⁇ 5 Torr (0 .5+ 0.1 psia) and the manifold flow rate is 20+ 2 slm (-42+ 4 scfh) .
  • a variety of manifold pressures and flo ⁇ w rates may be used, however, low pressures are typical ILy desired.
  • the manifold valves 30a-30g of the system operate independently of each other to place connected components, such as components 82, 84 and 86, into and out of fluid communication with the manifold 12 . Therefore, an advantage of the system of the present invention is that one component may be removed -without shutting down the entire system 10.
  • the manifold valve 30 connected to the component to be removed may be closed such that the component i s no longer in fluid communication with the connected inlet 22.
  • the component may then be removed from the system and utilized for semiconductor device manufacturing without disrupting the vacuum.
  • a set of components from, for example, one reaction chamber may be removed after cont minant reduction while another set from another chamber, for example, are still undergoing contaminant reduction.
  • replacement components may be connected to the manifold 12 to replace the removed set. In this manner, components belonging to semiconductor device manufacturing equipment may efficiently undergo contaminant reduction.
  • Valves connected to the rotation assemblies are opened slowly to vent out the components to atmosphere before removal.
  • valve 122 connected to rotation assembly 82a via fitting 120 (Fig. 6a-6b) , is opened to vent out rotation assembly 82a.
  • Valve 123 connected to rotation assembly 82b, is opened to vent out rotation assembly 82b.
  • the oven 46 is set at 65 °C. and has an oven pressure of 25+ 5 Torr (0.5 + 0.1 psia) . In one example, the oven flow rate is 14. l ⁇ 4.7 slm (30+ 10 scfh) .
  • the temperature and pressure may vary.
  • the components When the components have undergone contaminant reduction, they are removed from the system and are ready for use.
  • the components are connected to the manifold until it is time for use.
  • Components undergoing contaminant reduction in the system of the present invention in one example, remain under vacuum and exposed to the purge fluid for 30-35 days.
  • the components are stored in, for example, a nitrogen environment until it is time for use.
  • the amount of time for which the components undergo contaminant reduction may vary.
  • valve handles 39 imply manual control means for connecting components to manifold 12.
  • automated, computer and state macrine-controlled valve control is considered to be within a scope of the present invention. Therefore, the scope shtall only be determined by way of the appended claims.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Valve Housings (AREA)
  • Cleaning Or Drying Semiconductors (AREA)
  • Drying Of Semiconductors (AREA)

Abstract

A system, apparatus, and method for reducing contaminants of semiconductor device fabrication equipment components (82, 84, 86), featuring a manifold (12) having a passageway (14) in fluid communication with a plurality of inlets (22) and for providing a purge fluid to removably connected components to undergo contaminant reduction. The inlets are connected to a plurality of manifold valves (30) to which components are removably connected. The manifold valves are operable to place connected components into and out of fluid communication with the inlets and the passageway. A fluid source (20) supplies purge fluid to the manifold and a pump (32) is connected to the manifold to remove fluid from the system. In one embodiment, an oven (46) is connected to the system for outgassing and for reduction of moisture in additional components.

Description

Description
SYSTEM, APPARATUS AND METHOD FOR CONTAMINANT REDUCTION IN SEMICONDUCTOR DEVICE FABRICATION EQUIPMENT COMPONENTS
TECHNICAL FIELD The invention relates to semiconductor device fabrication equipment in general, and, in particular, to a system, apparatus, and method for contaminant reduction of semiconductor device fabrication equipment components.
BACKGROUND OF THE INVENTION Semiconductor device fabrication equipment components tend to accumulate contaminants, through for example, adsorption and absorption, before, during, and/or after the operation of the fabrication equipment. Such contaminants include, for example, moisture, oxygen, atmosphere, or any other gases. Possible contaminant sources are process gases as well as the atmosphere. Even components that have been cleaned, by cleaning processes known in the art, or that are new, are subject to accumulation of contaminants. Thus, the components of the semiconductor device fabrication equipment become a source of contaminants, in addition to process gases.
Contaminants on components are undesirable for at least the reasons that they degrade the quality of the fabricated semiconductor device manufactured and reduce the efficiency of the fabrication process. Where the method of semiconductor device fabrication involves depositing epitaxially-grown silicon germanium (SiGe) on a silicon substrate in a chemical vapor deposition (CVD) reactor, during SiGe deposition, oxygen present in the CVD reactor is typically incorporated into the SiGe film. Elevated oxygen levels present in the CVD reaction chamber used to deposit SiGe causes numerous problems in the SiGe films produced in the CVD reactor chamber. Among these problems are elevated sheet resistance of the SiGe p-type base and poor crystal, quality. Additionally, as the amount of absorbed or adsorbed contaminants, such as oxygen, increases, the amount of t±me for which the reactor must be taken offline typically increases in order to achieve acceptable oxygen levels in SiGe films. While the reactor is offline, it is disassembled to remove contaminants, reassembled, and then tested. The longer the reactor is offline, the less cost effective manufacturing becomes, as an offline reactor cannot be used for manufacturing semiconductor chips. Also, elevated contaminant levels in the reactor components may lead to early reactor failure and a decreased reactor lifetime. Therefore, it is an object of the present invention to provide a system, method, and apparatus for reduction or- elimination of contaminants found in semiconductor device fabrication equipment components. It is another object of the present invention to reduce or: eliminate levels of contaminants on semiconductor device fabrication equipment components. It is a further object of the present invention to improve the quality of semiconductor devices manufactured with semiconductor device fabrication equipment . Additional objects of the present invention are to reduce preventative maintenance recovery time, process recovery time, and mean time to repair (MTTR) and to increase mean time between interrupt (MTBI) and mean time between cleans (MTBC) . SUMMARY OF THE INVENTION The above and other objects have been met with a method, system, and apparatus each of which, in one exemplary embodiment, feature a manifold which associates a plurality of components together so that they may be selectively placed into and out of fluid communication with fluid, such as a purge fluid, introduced into a main passageway for reducing the amount of contaminants present on surfaces of the components. The purge fluid may include a gas selected from a variety of different types of gases, including nitrogen. The purge fluid may be inert. The manifold has a pair of capped ends, a main passageway, a plurality of inlets in fluid communication with the main passageway, manifold valves connected to the plurality of inlets to which semiconductor device fabrication equipment components are connectable, and an exhaust fitting connected to the manifold at a location downstream from the inlet closest to the capped end. In the system, one of the capped ends is connected to a fluid source and the exhaust fitting is connected to a pump which pumps fluid introduced into the manifold out of the manifold under vacuum. The term vacuum, as referred to in the description of the present invention, means a low pressure environment . In one embodiment, the system and apparatus further include caps which are connectable to the manifold valves and to a type of component to undergo contaminant reduction having a pair of openings. When a component having two openings, such as a ball valve or a pressure control valve, is connected to a manifold valve for contaminant reduction, one end of the component is connected to the manifold valve at an end having a first opening and the other end of the component having a second opening is capped with a cap to maintain the vacuum within the manifold by preventing atmospheric particles from entering the component and manifold. When the component is a rotation assembly, one end of the rotation assembly including an opening is connected to the manifold valve, while the other end is typically already closed and thus does not require a cap. When a component is not connected to a particular manifold valve, an uncovered manifold valve opening may be capped to maintain the vacuum within the system when the valve is in an open position. Cap valves may be connected to the caps. When the manifold is in use, a vacuum typically exists within the system. When components are to be removed from the manifold, the cap valve is opened to slowly let air into the component and to vent the component out to atmosphere. In another embodiment, the system includes an oven connected to the pump for outgassing components of semiconductor device fabrication equipment . In operation, a purge fluid, such as nitrogen gas, is introduced into the manifold. Nitrogen gas, in particular nitrogen gas introduced in a vacuum, assists in the removal of oxygen from surfaces of the components. Components to undergo contaminant reduction are connected to the manifold valves. In one example, three sets of components (each set including, for example, two of the same type of component and each component having at least one opening) are connected to the manifold valves at the openings. For instance, two rotation assemblies, two ball valves, and two pressure control valves are connected to manifold valves of the system. The inlets of the manifold may be facing downwardly for connection to a manifold valve to which a rotation assembly is to be connected, or frontwardly for connection to a manifold valve to which a ball valve or pressure control valve is to be connected. As stated above, the manifold valves and components may be capped to maintain the vacuum within the system. Fluid is introduced into the main passageway of the manifold and is dispersed to inner surfaces of components via the manifold inlets and connected manifold valves which are in the open position. Fluid is pumped out of tie components, inlets, and manifold valves through the exhaust pipe connected to the pump. While the components are undergoing contaminant reduction, additional components may be disposed within the oven for outgassing. When the components have undergone contaminant reduction, they are removed from the system and are ready for use . The apparatus and system of the present invention is advantageous in at least that it reduces the amount of contaminants, such as oxygen, found on surfaces of semiconductor device fabrication equipment components. A reduction in oxygen within the components will result in an improvement in the quality of semiconductor devices manufactured by the equipment . Furthermore, trie present invention may reduce contaminants of more than one component and more than one type of component at a time. These components may be connected to the manifold valves, found within the oven, or both. Additionally, reduction of contaminants on components, with the system, apparatus, and method of the present invention, makes future removal of contaminants easier to achieve. Therefore, preventative maintenance recovery time, process recovery time, and mean time to repair (MTTR) are reduced. Further, mean time between interrupt (MTBI) of operation and mean time between cleans (MTBC) will increase as the semiconductor fabrication device equipment will not need to be maintained as often if contaminant reduction has been achieved with the present invention. The system and apparatus of the present invention may be utilized in conjunction with semiconductor device fabrication equipment components for several different types of semiconductor processes including, for example, SiGe, EPI, thin film, diffusion, etch, and implant processes .
BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of the system of the present invention. Fig. 2 is a front view of a portion of the system of Fig. 1. Fig. 3 is a top view of a portion of the system of Fig. 1. Fig. 4 is a perspective view of a frame of the system of Fig. 1. Fig. 5a is a perspective view of a manifold of the system of Fig. 1. Fig. 5b is a front view of the manifold of Fig. 2a. Fig. 5c is a top view of the manifold of Fig. 2b. Fig. 6a is a partial perspective view of the system of Fig. 1. Fig. 6b is an exploded view of Fig. 6a. Fig. 7a is another partial perspective view of the system of Fig. 1. Fig. 7b is an exploded view of Fig. 7a.
BEST MODE FOR CARRYING OUT THE INVENTION With reference to Fig. 1, the system 10 of the present invention is seen featuring a manifold 12. Referring to Fig. 1 and Figs. 5a-c, the manifold 12 is, for example, a stainless steel pipe, having a length of, for example, 178cm (70 1/8 inches) . The manifold 12 includes a main internal passageway 14 capped with first and second capped ends 16 and 18 (cap 18 is not shown in Fig. 5a) , the first capped end 16 appearing as capped end 18 except for having an opening (not shown) connected to a fluid source 20, a plurality of inlets 22a-22g disposed in between the capped ends 16 and 18 and in fluid communication with the main passageway 14, and an exhaust fitting 24 disposed proximate to the second capped end 18 and downstream from the plurality of inlets 22a-22g, the exhaust fitting 24 being in fluid communication with the main passageway 14 and the inlets 22a-22g. Capped end 16 includes flange 26a and capped end 18 includes flange 26b. For example, flanges 26a and 26b are NW100 flanges. In one example, each inlet 22 is approximately 5cm (2 inches) long and has a flange, for example an NW40 flange, that has an opening that is approximately 4cm (1.6 inches) in diameter. In one example, the exhaust fitting 24 is approximately 8.9cm (3 1/2 inches) long and has an opening that is approximately 5cm (1.97 inches) in diameter. Fluid source 20 is connected to the opening of the first capped end via fluid supply line 28. Referring to Figs. 1-3, a plurality of manifold valves 30a-30g is connected to the manifold inlets 22a- 22g respectively. Manifold valves 30a-30g may be connected to inlets 22a-22g via flange connections, or flange joints, 69a-69g (Figs. 2 and 3) . Manifold valves have handles 39a-39g (Fig. 1) which are operated to place the manifold 12 and connected components into and out of fluid communication with the inlets 22 and main passageway 14. The manifold valves 30 are, for example, ball valves. Each manifold valve 30 has a first end connected to one of the plurality of inlets 22a-22g and a second end to which a component is removably connected. Referring to Fig. 1, a pump 32, for example a roughing pump, is connected to the exhaust fitting 24 via a pipe 34. Other pressure reduction means for providing a reduced pressure within the manifold may be used. A pipe valve 36 is operable to place the exhaust fitting 24 into and out of fluid communication with the pipe 34 and pump 32. A primary pump controller 42, for example an EBARA A70W LCD controller (manufactured by Ebara Corp. Fujisawa, Japan) is seen disposed on the pump body 40 as a part of interface box 41. Wheels 44, which assist in transport of the pump 32, are connected to the pump body 40. A secondary pump controller 52, fox example an EBARA A70W LCD controller, is disposed on a top surface 54 of the oven 46. A user may choose to control the pump through the primary or secondary controller. In one embodiment, the system includes an oven 46 connected to the pump 32 via pipe 47. The oven 46 is, for example, a vacuum drying and outgas sing oven. One example of the oven is manufactured by Oven Technology Incorporated (Albuquerque, New Mexico) . The oven 46 includes handle 48 for opening oven door 50 to the oven chamber (not shown) . The oven also includes a controller, not shown here. Semiconductor fabrication equipment components, such as o-rings and internal chamber components comprising quartz, stainless steel, or silicon carbide (not shown) , are placed within the chamber of the oven for drying and outgassing. The oven
46 is connected to pump 32 via pipe 47 which, in turn, is connected to pipe 34. Pipe 47 includes valve 43 for placing the oven into and out of fluid communication with the pump 32. The oven is supported by base elements 54 forming a part of a frame 56 (Fig. 4) . With reference to Fig. 4, the exemplary frame 56 further includes pillars 58 and frame elements 60. Frame elements 6,0a-60f are connected via connection elements 62. In one example, connection elements are bolts. The frame 56 is, for example steel. Steel such as treated steel, including galvanized steel or Unistrut® (manufactured by Unistrut, Wayne, MI) may be used. Feet 64, located beneath the pillars 58, assist in distributing the load of the system 10. The manifold 12 is inserted within stirrups 66a- 66d connected to frame elements 60a-60d, respectively. The stirrups 66 support the manifold 12. In one example, the frame 56 is 143cm (56 3/8 inches) high, 56cm (22 1/8 inches) wide, and 139cm (54 3/4 inches) long. At the widest point the frame 56 is, for example, 67cm (26 3/16 inches) wide. In one example, the stirrups 66 are disposed 29cm ( 11 7/16 inches) from frame element 60e measured from a center print of the stirrup. Other frame dimensions may be used. With reference to Figs. 1 and 4, bracket 68 is utilized to support a flow regulator 70 (Fig. 1) which regulates the pressure of the fluid transported from the fluid source 20. In one example, the flow regulator 70 is a TESCOM 64-2600 series regulator (manufactured by Tescom Corp., Elk River, MN) . A column 72 (Fig. 1) is used to support a flow controller 74 which regulates the fluid flow. In one example, the column 72 has a height of approximately 37.5cm (14 3/4 inches) . The fluid source 20 is connected to the flow regulator 70 via supply line 28. The flow regulator 70 is connected to the flow controller 74 via supply line 28 which is, for example, connected in series. The supply line 28 is connected to the opening of the capped end 16. Bracket 76 supports a Mini Convectron® power supply 78 (manufactured by Granville Phillips, Longmont, CO) . The Mini Convectron Module 80, which measures the pressure of the manifold 12, is disposed on the manifold 12. With reference to Figs. 5a-5c, the manifold inlets 22a-22g are spaced to accommodate various types and sizes of semiconductor device fabrication equipment components. For example, inlets 22a-22g may be spaced apart to allow for connection of different types of components. In one example, inlets 22a and 22b are spaced apart by approximately 25.4cm (10 inches) , measured from a center point of each of the inlets. Such spacing allows for connection of a pair of semiconductor device fabrication equipment components, such as a pair of rotation assemblies 82a and 82b (Fig. 1) , as will be described below. Pairs of inlets, for example, inlets 22b and 22c, 22c and 22d, 22d and 22e, 22e and 22f, and 22f and 22g, are spaced apart by, for example, 22.4cm (8 13/16 inches) , measured from a center point of one inlet of each pair of inlets to a center point of the next inlet of the pair. Spacing between a pair of inlets allows for connection of various components to trie respective inlets. With reference to Fig. 1, spacing between inlets 22a and 22b allows for a pair of components, for example, a pair of rotation assemblies 82a and 82b, to be connected to inlets 22a and 22b. Spacing between inlets 22b and 22c allows for a pair of components, for example, rotation assembly 82b and a pressure control valve 84a, to be connected to inlets 22b and 22c, respectively. Spacing between inlets 22c and 22d allows for a pair of components, for example , pressure control valve 84a and a pressure control valve 84b, to be connected to inlets 22c and 22d. Spacing between inlets 22d and 22e allows for a pair of components, for example, pressure control valve 84b and a ball valve control valve 86a, to be connected in inlets 22d and 22e, respectively. Spacing between inlets 22d and 22e allows for a pair of components, for example, ball valve 86a and a ball valve 86b, to be connected to inlets 22d and 22e, respectively. Spacing between inlets 22f and 22g allows for a pair of components to be connected to each inlet, respectively. The example in Fig. 1 depicts pressure control valve 86b connected to inlet 22f and a cap 134e connected to inlet 22g. Instead of the cap, a component could be connected to inlet 22f . The type of component connected to each inlet may vary. The spacing between inlets should be sufficient to accommodate the desired components. Inlets may be downwardly facing, as are inlets 22a and 22b, or frontwardly facing as are inlets 22c-22g. The spacing and orientation of the inlets 22 assists in the accommodation of one or more sets of components. One or more components or various sets of components from semiconductor device fabrication equipment may undergo contaminant reduction at a single time. In the example of Fig. 1, three sets of components, each set including two components, namely one of a rotation assembly 82, a pressure control valve 84, and a chamber ball valve 86, are connected to the manifold for contaminant reduction. In the example shown in Fig. 1, downwardly facing inlets 22a and 22b may be dedicated to rotation assembly attachment. However, in the example, components connected to inlets 22c-22g are interchangeable in position at these inlets. Additional semiconductor device fabrication equipment components having a surface, for example an internal surface, and at least one opening leading to the surface may be connected to the manifold valves to undergo contaminant reduction. The term surface may be used to encompass any surface of the component to undergo contaminant reduction. Inlet 22a is spaced apart from flange 26a by, for example, 11.7cm (4 5/8 inches) from a center point of the inlet. Inlet 22g is spaced apart by, for example, 26.7cm (10 1/2 inches) from the flange 26b, measured from a center point of the inlet. Exhaust fitting 24 is spaced apart by, for example 9.68cm (3 13/16 inches) from flange 26b, measured from a center point of the fitting. Referring to Figs. 1-3, six manifold valves 30a-30g are depicted connected to various components. Rotation assemblies 82a and 82b, which are depicted in representational form, are connected to manifold valves 30a and 30b, respectively, at an opening of each of the rotation assemblies leading to an internal surface of the rotation assembly. Rotation assemblies 82a and 82b include the same elements and are connected to the manifold 12 in the same manner, thus the elements and the connection will be explained only with regard to one rotation assembly. Referring to Fig. 6a, manifold valve 30a is connected to downwardly facing inlet 22a at one end, and to rotation assembly 82a at another end. Downwardly facing inlet 22a assists in the connection of rotation assembly 82a to the manifold valve 30a, as t ie downwardly facing inlet supports a particular shape of the rotation assembly. Referring to Figs. 6a and 6b, rotation assembly 82a includes a rotation assembly body 96 . A rotation assembly cup 98 having an opening 83 extending through the cup to an internal surface 85 of the rotation assembly to undergo contaminant reduction, is connected to a top surface 100 of the body 96. Rotation assembly flange 97 is connected to the cup 98. Still referring to Figs. 6a-6b, rotation assembly 82a is seen connected to manifold valve 30a via, for example, fitting 120 and ball joint 102. The fitting 120 is connected to the ball joint 102, at one end, and to the manifold valve 30a, at another end, via flange joints 121 and 123, respectively. The fitting 120 is connected to a valve 122 via tubing 124. The ball joint 102 includes a ball joint flange 104 with bolt openings 106, a male connector 108, and flange 110 which is for example, a KF flange. The male connector is inserted, at one end, within opening 83 of rotation assembly cup 98 of rotation assembly 82a. At another end, the male connector 108 is inserted through ball joint flange opening 112 and flange 110. Bolts 114 are inserted through openings 106 of the ball joint flange and notches 118 of rotation assembly flange 97 to secure the -ball joint to the rotation assembly cup 98. Other types of connections, including other rotatable joints, may be utilized to connect each rotation assembly to one of the manifold valves. Referring back to Fig. 1, pressure control valves 84a and 84b, which are depicted in representational form, are connected to manifold 12 via manifold valves 30c and 30d, respectively. With reference to Fig. 7a and Fig. 7b, the connection of pressure control valve 84b to manifold 12 is depicted in detail . Pressure control valve 84a includes the same components as and is connected to manifold 12 in the same manner as pressure control valve 84b, thus the components and connection to the manifold 12 of the chamber -ball valves will be described in detail with regard to one of the pressure control valves only. The components and connection of pressure control valve 84b to manifold 12 is as follows. Pressure control valve 84b is connected to manifold valve 30d at a first opening 88 of the pressure control valve leading to an internal surface 90, seen in Fig. 7b. In addition to first opening 88 , pressure control valve 84b includes a second opening 126 to the interior surface 90. The end of the pressure control valve 84b connected to the manifold valve 30d is proximate the first opening 88 of the pressure control and includes a flange 77. Manifold valve 30d also includes a flange 79 which forms a flange connection or flange joint 155 (Fig. 7a.) with flange 77. The flange connection is, for example, a KF40 flange connection. The second opening 126 of pressure control valve 84b is closed during operation of the system to prevent fluid, such as atmospheric particles, from entering the system and to allow the system to operate under vacuum. Specifically, cap 134b of cap assembly 135b closes opening 126 <Fig. 7b) during operation of the system. Cap 134b includes a flange 130, which forms a flange connection 151 (Fi-g. 7a) with a flange 133 located on an end of the pressure control valve 84b proximate the second opening 126, and may comprise a metallic material . Chamber ball valves 86a and 86b, which are depicted in representational form, are connected to manifold 12 via manifold valves 30e and 3 Of, respectively (Fig. 1) . With reference to Fig. 7a and Fig. 7b, the connection of chamber ball valve 86a to manifold 12 is depicted in detail. Chamber ball valves 86a and 86b include the same components and are connected to manifold 12 in the same manner, tnus the components and connection to the manifold 12 of the chamber ball valves will be described in detail with regard to one of the chamber ball valves only. The components and connection of chamber ball valve 86a to manifold 12 is as follows. Chamber ball valve 86a is connected to manifold valve 30e at a first opening 92 of the chamber ball valve leading to an internal surface 94, seen in Fig. 7b. In addition to first opening 92, chamber ball valve 86a includes a second opening 128 to the interior surface 94. The end of the chamber ball valve 86a connected to the manifold valve 30e is proximate tre first opening 92 of chamber ball valve 86a and incluc3.es a flange 93. Manifold valve includes a flange 95 whioh forms a flange connection, or flange joint 157 (Fig. 7_a) , with flange 93. The flange connection is, for example, a KF40 flange connection. The second opening 128 of chamber ball valve 86a is closed during operation of the system to prevent fluids from escaping the system and to allow the system to operate under vacuum. Specifically, cap 134c of cap assembly 135c closes opening 128 during operation of the system. Cap 134c includes a flange 132, which forms a flange connection 153 (Fig. 7a) with a flange 135 located on an end of the chamber ball valve 86a proximate the second opening 128, and may comprise a metallic material. Referring to Fig. 2, cap assemblies 135a-135e are seen featuring valves, caps, and tubing. Valves 137a-137e are connected to the caps 134a-134e, respectively, via tubing 139a-139e. Gas may be vented to each component through the corresponding valve 137a-137e and via the tubing elements 139a-139e, as will be described below. Where a manifold valve lacks a connected component, as with manifold valve 30g, a cap such as cap 134e, may be used to seal an opening of the manifold valve. A cap is not required to seal an opening of the manifold valve 30g, as the valve 30g may be placed in a closed position by adjustment with handle 39g (Fig. 1) to prevent fluid, such as atmospheric particles, from entering the manifold valve. Still referring to Fig. 2, cap assembly 135e may be removed from manifold valve 30g so that a residual gas analyzer may be connected to manifold valve 30g to analyze gas within the manifold 12. With reference to Fig. 1, in operation of the system, components desired to undergo contaminant reduction are connected to the manifold valves. In Fig. 1, components, including for example, one of a rotation assembly 82, a pressure control valve 84, and a chamber ball valve 86, are connected to the manifold valves 30a- 30f . A purge fluid, such as nitrogen gas, an inert gas, or another type of gas or other purge substance, is introduced into the manifold 12 for reducing contaminants present on the components . The following example is described with the use of nitrogen, however, other purge fluids may be used. Nitrogen gas is advantageous as a purge fluid as it assists in the removal of oxygen from surfaces of the components in the system. In one example, nitrogen is contained within the fluid source 20 at, for example, a pressure ranging from approximately 3620 Torr to 5171 Torr (70 psig to 100 psig) . Supply line 28 transports the nitrogen from the nitrogen source 20 to flow regulator 70 which regulates the flow of gas to, for example, approximately 259 Torr + 52 Torr (5+ 1 psig) . The regulated nitrogen gas is transported from the nitrogen regulator 70 to the flow controller 74.
From the flow controller 74, the gas is transported to the opening of capped end 16 via supply line 28. Nitrogen is introduced into the main passageway 14 as well as to the connected components via the plurality of inlets 22a-22f and manifold valves 30a-30f . In the example of Fig. 1, manifold valve 30g lacks a component, but may still be placed in fluid communication with the nitrogen, as described above. Inlets and manifold valves include passageways through which fluid is transported. Inlets 22a-22g include passageways 23a-23g, seen in Figs. 5a-5c. With regard to manifold valves 30a, 30d and 30e, passageways are seen as elements 61, 63, and 65 (Fig. 6b and Fig. 7b) , respectively. The other manifold valves include passageways which are not depicted. The fluid travels along the passageways of the inlets and manifold valves and reaches the internal surfaces of the components. With the introduction of the purge fluid under vacuum, oxygen is removed from the internal surfaces of the components. Fluid, such as oxygen gas, removed from the surfaces, is pumped out of the components 82a, 82b, 84a, 84b, 86a, and 86b, inlets 22a- 22g and manifold valves 30a-30g, through the exhaust pipe 24 connected to the pump 32. The system operates under a vacuum. Zn one example, the manifold pressure is 25± 5 Torr (0 .5+ 0.1 psia) and the manifold flow rate is 20+ 2 slm (-42+ 4 scfh) . A variety of manifold pressures and flo^w rates may be used, however, low pressures are typical ILy desired. The manifold valves 30a-30g of the system operate independently of each other to place connected components, such as components 82, 84 and 86, into and out of fluid communication with the manifold 12 . Therefore, an advantage of the system of the present invention is that one component may be removed -without shutting down the entire system 10. Specifical dy, the manifold valve 30 connected to the component to be removed may be closed such that the component i s no longer in fluid communication with the connected inlet 22. The component may then be removed from the system and utilized for semiconductor device manufacturing without disrupting the vacuum. Further, because a plurality of components may undergo contaminant reduction by the system 10 of the present invention, a set of components from, for example, one reaction chamber, may be removed after cont minant reduction while another set from another chamber, for example, are still undergoing contaminant reduction. Additionally, replacement components may be connected to the manifold 12 to replace the removed set. In this manner, components belonging to semiconductor device manufacturing equipment may efficiently undergo contaminant reduction. When the system is in use, a vacuum environment typically exists within the system, including the manifold 12 and the connected components. Therefore, before a component is removed from the system, it is desirable that the component is slowly vented out to atmosphere. Valves connected to the rotation assemblies are opened slowly to vent out the components to atmosphere before removal. For example, valve 122, connected to rotation assembly 82a via fitting 120 (Fig. 6a-6b) , is opened to vent out rotation assembly 82a. Valve 123, connected to rotation assembly 82b, is opened to vent out rotation assembly 82b. Valves 137a-137e (Fig. 1) of cap assemblies 135a-135e (Fig. 2), which are connected to pressure control valves 84a and 84b, chamber ball valves 86a and 86b, and manifold valve 30g, respectively, are opened slowly to vent out the components to atmosphere before removal or to test the composition of gas within the manifold valve 12. Before opening each of the valves, the corresponding manifold valve is closed. While the connected components are undergoing contaminant reduction, additional components, such as o- rings, may be disposed within the oven 46 for moisture reduction and outgassing. In one example, the oven is set at 65 °C. and has an oven pressure of 25+ 5 Torr (0.5 + 0.1 psia) . In one example, the oven flow rate is 14. l± 4.7 slm (30+ 10 scfh) . The temperature and pressure may vary. When the components have undergone contaminant reduction, they are removed from the system and are ready for use. In one example, the components are connected to the manifold until it is time for use. Components undergoing contaminant reduction in the system of the present invention, in one example, remain under vacuum and exposed to the purge fluid for 30-35 days. In another example, the components are stored in, for example, a nitrogen environment until it is time for use. The amount of time for which the components undergo contaminant reduction may vary. Although certain embodiments have been described for illustration, a skilled artisan will recognize various means for accomplishing a. similar purpose. For example, valve handles 39 imply manual control means for connecting components to manifold 12. However, automated, computer and state macrine-controlled valve control is considered to be within a scope of the present invention. Therefore, the scope shtall only be determined by way of the appended claims.

Claims

Claims
1. A system for contaminant reduction of semiconductor device fabrication equipment components, comprising: a manifold having a main passageway with first and second capped ends, said first capped end configured to accept a purge fluid, a plurality of inlets disposed in between said capped ends in fluid communication with said main passageway, and an exhaust fitting disposed downstream from said plurality of inlets and being in fluid communication with said main passageway; a plurality of manifold valves, each manifold valve having a first end connected to one of said plurality of inlets and a second end to which a semiconductor device fabrication equipment component having a contaminated surface for contaminant reduction and at least one opening is removably connectable at said at least one opening, and each manifold valve being operable to place one of said plurality of inlets into and out of fluid communication with said surface of said removably connectable component; a purge fluid source; and a pump .
2. The system of claim 1 wherein said plurality of inlets are spaced apart such that two sets of components are connectable to said manifold valves, each set including at least two different types of components.
3. The system of claim 1 further comprising a plurality of caps, each of said caps removably connectable to said second end of said manifold valves and to components having two openings .
4. The system of claim 3 wherein one of said caps is connected to one end of one of said components when another end of said one of said components is connected to one of said manifold valves.
5. The system of claim 3 wherein one of said caps is connected to said second end of one of said manifold valves in the absence of one of said components connected to said one of said manifold valves.
6. The system of claim 3 wherein one of said caps forms a flange connection with one of said components when connected to said one of said components, and a flange connection with one of said manifold valves when connected to said second end of said one of said manifold valves .
7. The system of claim 3 wherein each of said plurality of caps is connected to a cap valve.
8. The system of claim 7 wherein each of said plurality of caps is connected to said cap valve via tubing.
9. The system of claim 1 wherein at least one of said inlets is a downwardly facing inlet.
10. The system of claim 1 wherein at least one of said inlet is a frontwardly facing inlet .
11. The system of claim 1 wherein one of said components is a rotation assembly.
12. The system of claim 11 wherein said rotation assembly is connected to one of said manifold valves with a ball joint.
13. The system of claim 12 wherein said ball joint includes a ball flange, a male connector, and a flange .
14. The system of claim 11 wherein said rotation assembly is connected to one of said manifold valves with a rotatable joint.
15. The system of claim 11 wherein one of said inlets is downwardly facing and said rotation assembly is connected to said downwardly facing inlet.
16. The system of claim 1 wherein said one of said components is a chamber ball valve.
17. The system of claim 16 wherein said chamber ball valve is connected to one of said manifold valves with a flange connection.
18. The system of claim 17 wherein said flange connection is a KF40 flange joint.
19. The system of claim 16 wherein one of said inlets is frontwardly facing and said ball valve is connected to said frontwardly facing inlet .
20. The system of claim 1 wherein one of said components is a pressure control valve.
21. The system of claim 20 wherein said pressure control valve is connected to one of said manifold valves with a flange connection.
22. The system of claim 21 wherein said flange connection is a KF40 flange joint.
23. The system of claim 20 wherein one of said inlets is frontwardly facing and said pressure control valve is connected to said frontwardly facing inlet .
24. The system according to claim 1 wherein said inlets include two downwardly facing inlets and four frontwardly facing inlets.
25. The system according to claim 24 wherein said components include a pair of rotation assemblies connected to a first pair of manifold valves which are connected to said two downwardly facing inlets, a pair of pressure control valves connected to a second pair of manifold valves which are connected to two of said frontwardly facing inlets, and a pair of chamber ball valves connected to a third pair of manifold valves which are connected to another two of said frontwardly facing inlets .
26. The system according to claim 1 wherein said manifold includes six inlets, at least one of which is downwardly facing and at least one of which is frontwardly facing.
27. The system according to claim 1 wherein said components include different types of components and wherein two sets of each different type of component are connected to said manifold valves .
28. The system of claim 1 wherein one of said inlets is an analyzer port .
29. The system of claim 1 further comprising a frame supporting said manifold.
30. The system of claim 29 wherein said frame includes stirrups within which said manifold is inserted.
31. The system of claim 29 wherein said frame is steel.
32. The system of claim 29 wherein said frame comprises frame elements bolted together.
33. The system of claim 29 wherein said frame includes a base.
34. The system of claim 1 further comprising a first pipe connected to said pump and to said exhaust fitting.
35. The system of claim 34 further comprising a pipe valve disposed on said pipe.
36. The system of claim 34 further comprising an oven and a second pipe, said second pipe connected to said first pipe and to said oven.
37. The system of claim 1 wherein said fluid source is a nitrogen source.
38. The system of claim 37 wherein said nitrogen source includes nitrogen ranging from 70 psig to 100 psig.
39. The system of claim 1 wherein said fluid source is an inert fluid source .
40. The system of claim 1 further comprising a flow regulator and a flow controller, wherein said fluid source is connected to said flow regulator and said flow controller is connected to said flow regulator and said opening in said capped end.
41. The system of claim 40 further comprising a fluid supply line connecting said fluid source to said flow regulator, connecting said flow regulator to said flow controller, and connecting said flow controller to said opening in said capped end.
42. The system of claim 40 wherein said flow regulator supplies fluid to said flow controller at approximately 5 psig.
43. The system of claim 1 further comprising an oven connected to said pump .
44. The system of claim 43 further comprising o-rings disposed in said oven for outgassing.
45. The system of claim 43 further comprising an oven controller.
46. The system of claim 1 further comprising a pump controller.
47. The system of claim 1 wherein said exhaust fitting is disposed proximate to said capped ends.
48. The system of claim 1 wherein said at least one opening of said semiconductor device fabrication equipment component leads to said surface for contaminant reduction.
49. The system of claim 1 wherein said surface for contaminant reduction is an internal surface.
50. An apparatus for contaminant reduction of semiconductor device fabrication equipment components, comprising: a manifold closed at one end and configured to accept a purge fluid at another end, a fluid passageway, a plurality of inlets, and a fluid exhaust fitting disposed downstream from said inlets, said inlets and said fluid exhaust fitting in fluid communication with said fluid passageway; and a plurality of manifold valves, each manifold valve being connected to one of said plurality of inlets and to each of which a semiconductor device fabrication equipment component having a surface for contaminant reduction is removably connectable, wherein said manifold valves are operable to place said removably connectable components into and out of fluid communication with said plurality of inlets.
51. The apparatus of claim 50 further comprising a plurality of caps, each of said caps removably connectable to said second end of said manifold valves and to at least one of said components.
52. The apparatus of claim 51 wherein one of said caps is connected to one end of one of said components when another end of said one of said components is connected to one of said manifold valves.
53. The apparatus of claim 51 wherein one of said caps is connected to said second end of one of said manifold valves in the absence of one of said components connected to said one of said manifold valves.
54. The apparatus of claim 51 wherein one of said caps forms a flange connection with one of said components when connected to said one of said components, and a flange connection with one of said manifold valves when connected to said second end of said one of said manifold valves .
55. The apparatus of claim 51 wherein each of said plurality of caps is connected to a cap valve.
56. The apparatus of claim 55 wherein each of said plurality of caps is connected to said cap valve via tubing .
57. The apparatus of claim 50 wherein at least one of said inlets is a downwardly facing inlet .
58. The apparatus of claim 57 wherein one of said components is a rotation assembly.
59. The apparatus of claim 58 wherein said rotation assembly is connected to one of said manifold valves with a ball joint.
60. The apparatus of claim 50 wherein at least one of said inlets is a frontwardly facing inlet.
61. The apparatus of claim 60 wherein said one of said components is a chamber ball valve.
62. The apparatus of claim 61 wherein said chamber ball valve is connected to one of said manifold valves with a flange connection.
63. The apparatus of claim 60 wherein said components include a pressure control valve.
64. The apparatus of claim 63 wherein said pressure control valve is connected to one of said manifold valves with a flange connection.
65. The apparatus of claim 50 wherein each of said semiconductor device fabrication equipment components includes an opening for connection to one of said manifold valves.
66 . The apparatus of claim 65 wherein each of said semiconductor device fabrication equipment component openings leads to an inner surface for contaminant reduction, said inner surface placed into and out of fluid communication with one of said plurality of inlets.
67. A method for reducing contaminants of semiconductor device fabrication equipment components, each component having a contaminated surface, with a manifold having a main passageway with first and second capped ends, said first capped end configured to accept a purge fluid source, a plurality of inlets disposed in between said capped ends in fluid communication with said main passageway, and an exhaust fitting configured to accept a pump, said exhaust fitting disposed downstream from said plurality of inlets and in fluid communication with said main passageway, comprising: providing said manifold; connecting a purge fluid source to said first capped end; connecting a pump to said exhaust fitting; connecting at least one semiconductor device fabrication equipment component to at least one of said plurality of inlets; releasing a purge fluid into said manifold; placing said at least one component in fluid communication with said at least one of said plurality of inlets; contacting said contaminated surface of said at least one component with said purge fluid surface; and pumping fluid from said manifold.
68. The method of claim 67 further comprising placing said at least one component out of fluid communication with said manifold.
69. The method of claim 67 further comprising removing said at least one component from said manifold.
70. The method of claim 67 wherein the step of connecting at least one component to at least one of said plurality of inlets occurs at an opening of said at least one component .
71. The method of claim 67 wherein said surface for cleaning is an internal surface.
72. The method of claim 67 wherein contacting said contaminated surface with said purge fluid occurs under vacuum.
PCT/US2005/006305 2004-03-15 2005-02-25 System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components WO2005091892A2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
EP20050723954 EP1784595A2 (en) 2004-03-15 2005-02-25 System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US10/801,435 2004-03-15
US10/801,435 US7044147B2 (en) 2004-03-15 2004-03-15 System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components

Publications (2)

Publication Number Publication Date
WO2005091892A2 true WO2005091892A2 (en) 2005-10-06
WO2005091892A3 WO2005091892A3 (en) 2006-03-23

Family

ID=34920853

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2005/006305 WO2005091892A2 (en) 2004-03-15 2005-02-25 System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components

Country Status (5)

Country Link
US (2) US7044147B2 (en)
EP (1) EP1784595A2 (en)
CN (1) CN1954167A (en)
TW (1) TW200535958A (en)
WO (1) WO2005091892A2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7540298B2 (en) 2004-03-15 2009-06-02 Atmel Corporation System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20090151623A1 (en) * 2007-12-12 2009-06-18 Atmel Corporation Formation and applications of high-quality epitaxial films
US20090189159A1 (en) * 2008-01-28 2009-07-30 Atmel Corporation Gettering layer on substrate
US8042566B2 (en) * 2008-07-23 2011-10-25 Atmel Corporation Ex-situ component recovery
KR200467280Y1 (en) * 2010-02-19 2013-06-04 최육남 Pipe branching apparatus
US8893923B2 (en) * 2012-11-28 2014-11-25 Intermolecular, Inc. Methods and systems for dispensing different liquids for high productivity combinatorial processing

Family Cites Families (18)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2122738A5 (en) * 1971-01-21 1972-09-01 Corobit Anstalt
US4352532A (en) * 1980-09-15 1982-10-05 Robertshaw Controls Company Manifolding means for electrical and/or pneumatic control units and parts and methods therefor
US4383547A (en) * 1981-03-27 1983-05-17 Valin Corporation Purging apparatus
US4437479A (en) * 1981-12-30 1984-03-20 Atcor Decontamination apparatus for semiconductor wafer handling equipment
US4852516A (en) * 1986-05-19 1989-08-01 Machine Technology, Inc. Modular processing apparatus for processing semiconductor wafers
US5137047A (en) * 1990-08-24 1992-08-11 Mark George Delivery of reactive gas from gas pad to process tool
US5453124A (en) * 1992-12-30 1995-09-26 Texas Instruments Incorporated Programmable multizone gas injector for single-wafer semiconductor processing equipment
US5449294A (en) * 1993-03-26 1995-09-12 Texas Instruments Incorporated Multiple valve assembly and process
WO1997037182A1 (en) * 1996-03-29 1997-10-09 Minnesota Mining And Manufacturing Company Apparatus and method for drying a coating on a substrate employing multiple drying subzones
US6099599A (en) * 1996-05-08 2000-08-08 Industrial Technology Research Institute Semiconductor device fabrication system
US5992463A (en) * 1996-10-30 1999-11-30 Unit Instruments, Inc. Gas panel
US6598279B1 (en) * 1998-08-21 2003-07-29 Micron Technology, Inc. Multiple connection socket assembly for semiconductor fabrication equipment and methods employing same
US6199255B1 (en) * 1999-10-06 2001-03-13 Taiwan Semiconductor Manufacturing Company, Ltd Apparatus for disassembling an injector head
US6442867B2 (en) * 2000-01-04 2002-09-03 Texas Instruments Incorporated Apparatus and method for cleaning a vertical furnace pedestal and cap
US6325886B1 (en) * 2000-02-14 2001-12-04 Redwood Microsystems, Inc. Method for attaching a micromechanical device to a manifold, and fluid control system produced thereby
US6607605B2 (en) * 2000-08-31 2003-08-19 Chemtrace Corporation Cleaning of semiconductor process equipment chamber parts using organic solvents
US6349744B1 (en) * 2000-10-13 2002-02-26 Mks Instruments, Inc. Manifold for modular gas box system
US7044147B2 (en) 2004-03-15 2006-05-16 Atmel Corporation System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
None

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7540298B2 (en) 2004-03-15 2009-06-02 Atmel Corporation System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components

Also Published As

Publication number Publication date
US20060169318A1 (en) 2006-08-03
US20050199284A1 (en) 2005-09-15
CN1954167A (en) 2007-04-25
TW200535958A (en) 2005-11-01
US7044147B2 (en) 2006-05-16
US7540298B2 (en) 2009-06-02
EP1784595A2 (en) 2007-05-16
WO2005091892A3 (en) 2006-03-23

Similar Documents

Publication Publication Date Title
US7540298B2 (en) System, apparatus and method for contaminant reduction in semiconductor device fabrication equipment components
US7066703B2 (en) Chuck transport method and system
EP0529982B1 (en) Exhaust apparatus for epitaxial growth system.
US5758680A (en) Method and apparatus for pressure control in vacuum processors
EP0938634B1 (en) Gas panel
KR102467351B1 (en) Load port operation in electronic device manufacturing apparatus, systems, and methods
EP3652778A1 (en) Gas delivery system for high pressure processing chamber
US8011381B2 (en) Balanced purge slit valve
EP2046502A2 (en) System and method for treating surfaces of components
US20130239889A1 (en) Valve purge assembly for semiconductor manufacturing tools
US5803107A (en) Method and apparatus for pressure control in vacuum processors
US6701972B2 (en) Vacuum load lock, system including vacuum load lock, and associated methods
JP5224567B2 (en) Substrate processing apparatus, substrate processing method, and semiconductor device manufacturing method
US20080302426A1 (en) System and method of securing removable components for distribution of fluids
US8372209B2 (en) Ex-situ component recovery
US6478040B1 (en) Gas supplying apparatus and gas substitution method
WO1996034705A1 (en) Mfc-quick change method and apparatus
WO2023069187A1 (en) . methods, systems, and apparatus for conducting a radical treatment operation prior to conducting an annealing operation
US4539062A (en) Modular plasma reactor with local atmosphere
JPH10223719A (en) Substrate carrier system, substrate processor and substrate carrier method
KR100513488B1 (en) Apparatus for supplying a source gas
US6189238B1 (en) Portable purge system for transporting materials
US20220242706A1 (en) Cathode exchange mechanism to improve preventative maintenance time for cluster system
EP0461406A1 (en) Single ended ultra-high vacuum chemical vapor deposition (UHV/CVD) reactor
JPH09306851A (en) Decompression exhaust system and decompression vapor-phase treating apparatus

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A2

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SM SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A2

Designated state(s): GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IS IT LT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

DPEN Request for preliminary examination filed prior to expiration of 19th month from priority date (pct application filed from 20040101)
WWE Wipo information: entry into national phase

Ref document number: 2005723954

Country of ref document: EP

NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Country of ref document: DE

WWE Wipo information: entry into national phase

Ref document number: 200580015569.4

Country of ref document: CN

121 Ep: the epo has been informed by wipo that ep was designated in this application
WWP Wipo information: published in national office

Ref document number: 2005723954

Country of ref document: EP