WO2008139379A2 - Spectrum detector for uv radiation and manufacturing method therefore - Google Patents

Spectrum detector for uv radiation and manufacturing method therefore Download PDF

Info

Publication number
WO2008139379A2
WO2008139379A2 PCT/IB2008/051796 IB2008051796W WO2008139379A2 WO 2008139379 A2 WO2008139379 A2 WO 2008139379A2 IB 2008051796 W IB2008051796 W IB 2008051796W WO 2008139379 A2 WO2008139379 A2 WO 2008139379A2
Authority
WO
WIPO (PCT)
Prior art keywords
light
wavelength converting
wavelength
converting plate
spectrum detector
Prior art date
Application number
PCT/IB2008/051796
Other languages
French (fr)
Other versions
WO2008139379A3 (en
Inventor
Eduard J. Meijer
Original Assignee
Koninklijke Philips Electronics N.V.
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 Koninklijke Philips Electronics N.V. filed Critical Koninklijke Philips Electronics N.V.
Publication of WO2008139379A2 publication Critical patent/WO2008139379A2/en
Publication of WO2008139379A3 publication Critical patent/WO2008139379A3/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
    • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
    • H01L27/144—Devices controlled by radiation
    • H01L27/1446—Devices controlled by radiation in a repetitive configuration
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J1/00—Photometry, e.g. photographic exposure meter
    • G01J1/58—Photometry, e.g. photographic exposure meter using luminescence generated by light
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/02—Details
    • G01J3/0256—Compact construction
    • G01J3/0259—Monolithic
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
    • G01J3/00—Spectrometry; Spectrophotometry; Monochromators; Measuring colours
    • G01J3/28—Investigating the spectrum
    • G01J3/2803—Investigating the spectrum using photoelectric array detector
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L31/00—Semiconductor devices sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation; Processes or apparatus specially adapted for the manufacture or treatment thereof or of parts thereof; Details thereof
    • H01L31/02—Details
    • H01L31/0232—Optical elements or arrangements associated with the device
    • H01L31/02322—Optical elements or arrangements associated with the device comprising luminescent members, e.g. fluorescent sheets upon the device

Definitions

  • the present invention relates to a semiconductor-based spectrum detector especially suitable for detecting a spectral distribution in the UV-range, and a method for manufacturing such a spectrum detector.
  • UV light is increasingly being used for a variety of applications, ranging from health care to water purification. There is also an ever increasing awareness of the risks connected with an excessive skin exposure by especially some wavelength ranges within what is usually referred to as the ultraviolet range.
  • spectrometer or spectrum detector. Available spectrometers are typically relatively bulky and expensive and not well suited for use in small devices or consumer market products.
  • Semiconductor-based photodiodes are, on the other hand, cost efficient and can be made very compact.
  • photodiodes degrade when exposed to energetic light, such as blue or, even more so, ultraviolet light.
  • silicon based photodiodes generally have a decreased sensitivity towards the UV region due to the fact that UV-photons are absorbed very much at the surface of the silicon, which requires that a very shallow junction diode be used to accurately detect these photons.
  • a very shallow junction is very difficult to make.
  • US 6 211 524 discloses a photodiode-based spectrum detector in the form of a detector array comprising a plurality of photodiodes each having a luminescent material layer interposed between the photodiode and a source of incident radiation. By selecting each luminescent material layer such that it absorbs at a different selected wavelength, a spectrum of wavelengths can be read simultaneously.
  • a general object of the present invention is to provide an improved spectrum detector for the UV-range and, in particular, a more compact and/or cost-efficient detector.
  • a method for manufacturing a spectrum detection device for enabling determination of a spectral distribution in the UV-range, comprising the steps of providing a semiconductor substrate having first and second light-sensing structures formed therein; covering the first and second light-sensing structures with a wavelength converting plate; and forming a first optical filter on a portion of the wavelength converting plate corresponding to the first light-sensing structure, and a second optical filter on a portion of the wavelength converting plate corresponding to the second light-sensing structure, the first and second optical filters being configured to selectively transmit light in first and second different wavelength ranges, respectively.
  • the present invention is based upon the realization that an improved spectrum detector, especially suitable for detecting a spectral distribution in the UV-range, can be achieved by using a single wavelength converting plate for covering the different light- sensing structures in the spectrum detector and forming optical filters on the wavelength converting plate for selecting the wavelength range to be sensed by the different light-sensing structures.
  • the spectrum of the incident light can then be determined by combining the outputs of the first and second light-sensing structures.
  • the spectrum can be determined with a higher resolution.
  • the semiconductor substrate may be made of any suitable semiconductor, in which a light-sensing structure can be formed, including, for example, Si, GaAs, InP, SiC, GaP, TiO 2 , GaN, AlGaN etc.
  • the light-sensing structures may, in principle, be any kind of semiconductor structure, which reacts on radiation.
  • Such structures include, for example, "ordinary” diodes, and transistors etc.
  • dedicated semiconductor elements such as photodiodes, CCD-elements, bipolar phototransistors, photosensitive field-effect transistor etc is preferred.
  • the optical filters are preferably bandpass filters in the form of interference filters, which may be realized by alternating providing several layers of dielectric materials having different refractive indices.
  • the wavelength range transmitted by the filter may then be selected by suitably selecting the thicknesses of the layers.
  • the filter may include transparent metal layers, whereby an improved out-of-band blocking may be achieved as compared to the all-dielectric filters.
  • an optical filter made of all inorganic materials would be preferable, since organic materials are generally more prone to being degraded when subjected to highly energetic radiation, such as UV-light. It should be noted than many types of optical band-pass filters exist and are well-known to the skilled person.
  • the optical filters may be formed on the wavelength converting plate after having attached the wavelength converting plate to the semiconductor substrate, or, alternatively, prior to attaching the wavelength converting plate to the semiconductor substrate.
  • the optical filters after having attached the wavelength converting plate to the semiconductor substrate, because it is generally easier to align a photo mask to structures on the semiconductor substrate than to align a plate to be attached thereto.
  • the method according to the present invention may further comprise the step of forming a cavity in the wavelength converting plate between the first and second portions thereof to prevent light generated in the first portion from reaching the second light-sensing structure and vice versa.
  • the method may further include the step of forming a barrier in the semiconductor substrate between the light-sensing structures formed therein.
  • This barrier may, for example, be formed by etching the semiconductor substrate so that recesses are formed therein, and subsequently building the light-sensing structures in the recesses.
  • the etching may be performed through isotropic etching using, for example, CF 4 etch (dry etch) or a mixture of HydroFluoric Acid (HF), Nitric Acid (HNO3) and acetic acid (CH 3 COOH), or through anisotropic etching using, for example, KOH.
  • a spectrum detector for enabling determination of a spectral distribution in the UV-range, comprising a semiconductor substrate having first and second light-sensing structures formed therein; a first part of a wavelength converting plate covering the first light-sensing structure, and a first optical filter provided on the first part of the wavelength converting plate; and a second part of the wavelength converting plate covering the second light-sensing structure, and a second optical filter provided on the second part of the wavelength converting plate, wherein the first optical filter is configured to selectively transmit light in a first wavelength range, and the second optical filter is configured to selectively transmit light in a second wavelength range, the second wavelength range being different from the first wavelength range.
  • the wavelength converting plate may advantageously be a ceramic plate having a wavelength-converting agent embedded therein.
  • a ceramic plate can be treated, for example polished, to achieve a sufficiently smooth surface for enabling formation of optical filters directly thereon.
  • each of the optical filters may be configured to reflect light being generated in the wavelength converting plate.
  • the efficiency and accuracy of the spectrum detector can be further increased, since it is ensured that practically every photon generated in the wavelength converting plate reaches the relevant light-sensing structure.
  • the spectrum detector according to the invention may further comprise a shielding structure between the first and second light-sensing structures.
  • the shielding structure may advantageously be formed as a wall in the semiconductor substrate. Such a wall can, for example, be achieved by forming recesses in the semiconductor substrate before fabricating the light-sensing structures in the recesses. As a result thereof, the light-sensing structures are shielded from light intended for adjacent light-sensing structures.
  • each of the first and second parts of the wavelength converting plate may be included in an integral wavelength converting plate.
  • the first and second parts of the wavelength converting plate may be separated from each other, in order to reduce or eliminate cross-talk between neighboring spectrum detector "pixels".
  • the gap between the first and second parts of the wavelength converting plate may be filled with a substance, such as air, having a lower refractive index than the wavelength converting plate, such that total internal reflection occurs at the interface between the wavelength converting plate part and the gap.
  • a reflective material such as a metal, may be deposited on the surface of the wavelength converting plate part facing the gap between the first and second parts.
  • the spectrum detector according to the present invention may comprise a number of spectrum detector "pixels" which is larger than two.
  • Each pixel comprises, as described above, a light-sensing structure formed in a semiconductor substrate, a wavelength converting plate part provided on top of the sensing structure to convert light having a short wavelength impinging on the wavelength converting plate part to light having a longer wavelength, which is more suitable for the light-sensing structure, leading to a higher efficiency and increased stability of the light-sensing structure.
  • On top of the wavelength converting plate part is provided an optical filter which prevents light outside a selected wavelength range from passing through it and hitting the wavelength converting plate part.
  • a spectrum of the light hitting the spectrum detector can be formed by combining the outputs from the different light-sensing structures.
  • Fig. Ia is a schematic cross-section view of a spectrum detector according to an embodiment of the present invention
  • Fig. Ib is an enlarged view of a portion of the spectrum detector in fig. Ia;
  • Fig. Ic is a diagram schematically illustrating the frequency selection of the filters comprised in the spectrum detector in fig. Ia;
  • Fig. Id is a diagram schematically illustrating the frequency conversion occurring in the spectrum detector in fig. Ia;
  • Fig. 2 is a flow chart schematically illustrating a method for manufacturing a spectrum detector according to an embodiment of the present invention
  • Figs. 3a-d schematically illustrates the state of the spectrum detector after the corresponding method steps in fig. 2;
  • Fig. 4 is a cross-section view schematically illustrating another embodiment of the spectrum detector according to the invention, where light-shielding structures are provided between the light-sensing structures;
  • Fig. 5 is a cross-section view schematically illustrating a further embodiment of the spectrum detector according to the invention, where gaps have been formed between the light-sensing structures in order to prevent cross-talk.
  • a spectrum detector comprising a photodiode array formed on a silicon substrate, a luminescent ceramic plate, and non-organic interference filters. It should be noted that this by no means limits the scope of the present invention, which is equally applicable to spectrum detectors based on other semiconductors and having other types of wavelength converting plates and/or optical filters.
  • Figs, la-b schematically illustrate a portion of a spectrum detector 1 according to the present invention having three light-sensing structures in the form of photodiodes 2a-c formed in a semiconductor substrate 6.
  • the spectrum detector 1 further comprises a luminescent ceramic plate 3 covering the photodiodes 2a-c and optical interference filters 4a-c provided on top of the luminescent plate 3 so that incoming light (illustrated by the arrows in Fig. Ia) generally needs to pass through the optical filters 4a-c before reaching the luminescent plate 3.
  • fig. Ib which is an enlargement of the portion of the spectrum detector 1 indicated in fig. Ia, it is schematically illustrated how a relatively narrow wavelength range, centered around the wavelength X 1 , is permitted to pass through the filter 4a, while the remainder of the incoming light is reflected as indicated by the turning arrows in Fig. Ib.
  • the light Following passage through the optical filter 4a, the light, generally having a wavelength of ⁇ i, hits a wavelength converting substance embedded in the ceramic.
  • a wavelength converting substance embedded in the ceramic.
  • An exemplary position of this wavelength converting substance is indicated by an x in Fig. Ib.
  • the wavelength converting substance (for example phosphor) absorbs the light having wavelength X 1 , transitions to a more energetic state, and subsequently relaxes back to its ground state and emits light having a wavelength X L in the process.
  • the luminescent ceramic 3 is selected to convert incoming light having a short wavelength, for example in the UV-range, to light in a wavelength X L , which is more suitable for the photodiode 2a.
  • the wavelength X L converted to may typically be larger than 600 nm for a silicon photodiode.
  • the light generated in the luminescent ceramic plate 3 at the exemplary location x may be emitted Omni directionally as indicated by the rays 5a-c emanating from the location x.
  • the rays 5a-b generally directed towards the photodiode 2a will hit the photodiode 2a and contribute to the signal output by the photodiode 2a, and the rays 5c-d directed away from the photodiode 2a are, as illustrated in Fig. Ib, reflected in the optical filter 4a and redirected towards the photodiode 2a.
  • the outputs from the respective photodiodes 2a-c can be used to determine the spectrum of the incoming light. This is schematically illustrated in Fig. Ic, where a typical relation between the spectrum 10 of the incoming light and the wavelength ranges 11-13 permitted to pass through the optical filters 4a-c, respectively, is shown.
  • filters having relatively narrow bands and small out-of-band transmittance may advantageously be made by providing a number of layer pairs each including a transparent metal layer and a dielectric layer on top of the luminescent plate 3 on a portion thereof corresponding to a photodiode 2a- c.
  • the transmittance band of such a filter can, as is well known to the skilled person, typically be made narrower by suitably selecting the number of layer pairs and the thickness of the metal and the dielectric layer, respectively.
  • the amount of light reaching the luminescent plate 3 depends on the spectrum 10 of the incoming light and the transmittance bands 11-13 of the optical filters 4a-c, respectively.
  • the spectrum 15 of light absorbed in the luminescent plate 3 in the portion thereof corresponding to the photodiode 2a is shown as the section between the incoming spectrum 10 and the transmittance band 11 for the optical filter 4a. This light is absorbed by the luminescent plate 3 and re-emitted as converted light 16 having a center frequency of ⁇ L .
  • the luminescent plate 3 and the optical filters 4a-c should also preferably be made as stable as possible with respect to energetic radiation, such as UV-light. This may advantageously be achieved by providing the luminescent plate as a stable ceramic-based plate, and the optical filters as interference filters which are free from organic materials.
  • the optical filters 4a-c can be manufactured by alternating layers of different dielectrics, or dielectrics and metals, such as SiN, SiO, AI2O3, CaF 2 , BaF 2 , Ag, Al, Au etc. Many variations exist as is apparent to the skilled person.
  • Fig. 2 and figs. 3a-c illustrate a method for manufacturing a spectrum detector according to an embodiment of the present invention.
  • a silicon wafer comprising a plurality of photodiode arrays is provided in a first step 100.
  • the exemplary wafer 30 shown in fig. 3a will eventually be separated into a plurality of individual spectrum detector components.
  • Each such spectrum detector is represented by a square on the wafer 30, and each such square comprises an array of photodiodes, which is each indicated by a circle in fig. 3a.
  • the manufacturing of the spectrum detector 32 will be described with reference to the two photodiodes 35a-b in the spectrum detector 32 closest to the scribe lane 33.
  • a luminescent ceramic plate 3 is attached to the wafer by means of an optical bonding material 39.
  • the luminescent ceramic plate 3 can be attached directly to the top surface 36 of the wafer 30.
  • the luminescent ceramic plate 3 can be pre-polished, or can be polished following attachment to the wafer 30 to be sufficiently smooth to enable forming high quality interference filters directly on the plate 3.
  • the interference filters for selecting different wavelength ranges in the incoming light are formed in step 102.
  • These interference filters can be formed through various conventional methods, one of which is described herein.
  • Each spectrum detector 31, 32 on the wafer 30 has a number of photodiodes. Typically, these spectrum detectors 31, 32 are manufactured to be identical to each other. They then each have a number of photodiodes 35a-b which should have different optical filters. However, one or several photodiodes in each of the spectrum detectors should have identical optical filters.
  • the wafer can first be masked for formation of the first layer on the first photodiodes (one or several corresponding photodiodes in each spectrum detector), and then be masked for formation of the first layer on the second photodiodes (one or several corresponding photodiodes in each spectrum detector), etc. Although requiring several process steps, these are all performed on the wafer scale so that a large number of spectrum detectors can be processed simultaneously.
  • Fig. 3c the first layer 37 of the interference filter 38a for the photodiode 35a is shown.
  • step 103 the wafer is divided to form separate finished spectrum detector components 31, 32. This is schematically illustrated in
  • the step 102 of forming the interference filters may be performed before the step 101 of attaching the luminescent ceramic plate 3 to the wafer.
  • the positions of the interference filters 38a should correspond to the positions of the photodiodes 35 a.
  • the luminescent ceramic plate having the pre-formed interference filters 38a should be aligned with respect to the photodiodes 35a prior to attachment.
  • Figs. 4 and 5 schematically illustrate two exemplary embodiments of the spectrum detector according to the invention, in which different measures have been implemented for reducing the occurrence of so-called cross-talk between neighboring photodiodes.
  • a spectrum detector 45 comprising a semiconductor substrate 6, in which five photodiodes 35a-e are formed. As shown in fig. 3d, the spectrum detector 45 in fig. 4 further includes an optical bond layer 39, a luminescent ceramic plate 3 and one optical filter 38a-e for each photodiode 35a-e.
  • each photodiode 35a-e is surrounded by a barrier 46 (indicated between the photodiodes 35a and 35b) formed in the semiconductor substrate 6.
  • a barrier 46 indicated between the photodiodes 35a and 35b formed in the semiconductor substrate 6.
  • each photodiode 35a-e is substantially shielded from light generated in a portion of the luminescent plate 3 above a neighboring photodiode 35a-e.
  • FIG. 5 another exemplary spectrum detector 50 is schematically illustrated, which differs from that shown in Fig. 3d in that the additional process step of removing parts of the luminescent plate 3 between photodiodes 35a-e has been implemented.
  • gaps 51a-d between neighboring photodiodes 35a-e are formed.
  • light intended for a particular photodiode 35a-e can be largely confined within the part of the luminescent plate 3 corresponding to that photodiode.
  • This is schematically illustrated for the photodiode 35a in fig. 5 where a ray 52 which is generated in the luminescent plate 3 is first reflected in the optical filter 38a and then at the interface to the gap 51a before reaching the photodiode 35a where it correctly contributes to the output of the spectrum detector 50.

Abstract

A spectrum detector (1; 32; 45; 50), for enabling determination of a spectral distribution in the UV-range, comprising a semiconductor substrate (6) having first (2a; 35 a) and second (2b; 35b) light-sensing structures formed therein. A first part of a wavelength converting plate (3) covers the first light-sensing structure (2a; 35a), and a first optical filter (4a; 38a) is provided on the first part of the wavelength converting plate (3), and a second part of a wavelength converting plate (3) covers the second light-sensing structure (2b; 35b), and a second optical filter (4b; 38b) is provided on the second part of the wavelength converting plate (3). The first optical filter (4a; 38a) is configured to selectively transmit light in a first wavelength range (11), and the second optical filter (4b; 38b) is configured to selectively transmit light in a second wavelength range (12), the second wavelength range (12) being different from the first wavelength range (11).

Description

Spectrum detector and manufacturing method therefore
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a semiconductor-based spectrum detector especially suitable for detecting a spectral distribution in the UV-range, and a method for manufacturing such a spectrum detector.
TECHNICAL BACKGROUND
Ultraviolet (UV) light is increasingly being used for a variety of applications, ranging from health care to water purification. There is also an ever increasing awareness of the risks connected with an excessive skin exposure by especially some wavelength ranges within what is usually referred to as the ultraviolet range. In order to safely and effectively utilize UV light in various applications, there is often a need to measure the spectral distribution of the UV light by means of a so-called spectrometer or spectrum detector. Available spectrometers are typically relatively bulky and expensive and not well suited for use in small devices or consumer market products. Semiconductor-based photodiodes are, on the other hand, cost efficient and can be made very compact.
It has, however, been observed that such photodiodes degrade when exposed to energetic light, such as blue or, even more so, ultraviolet light. Furthermore, especially silicon based photodiodes generally have a decreased sensitivity towards the UV region due to the fact that UV-photons are absorbed very much at the surface of the silicon, which requires that a very shallow junction diode be used to accurately detect these photons. Unfortunately, such a very shallow junction is very difficult to make.
US 6 211 524 discloses a photodiode-based spectrum detector in the form of a detector array comprising a plurality of photodiodes each having a luminescent material layer interposed between the photodiode and a source of incident radiation. By selecting each luminescent material layer such that it absorbs at a different selected wavelength, a spectrum of wavelengths can be read simultaneously.
However, it is difficult to provide luminescent material layers having a very narrow absorption wavelength range. Therefore, a spectrum detector based on different luminescent material layers typically has a low spectral resolution. Furthermore, the requirement to apply different luminescent material layers to the different photodiodes limits the compactness and/or manufacturing cost achievable for this detector.
SUMMARY OF THE INVENTION In view of the above-mentioned and other drawbacks of the prior art, a general object of the present invention is to provide an improved spectrum detector for the UV-range and, in particular, a more compact and/or cost-efficient detector.
According to a first aspect of the present invention, these and other objects are achieved through a method for manufacturing a spectrum detection device, for enabling determination of a spectral distribution in the UV-range, comprising the steps of providing a semiconductor substrate having first and second light-sensing structures formed therein; covering the first and second light-sensing structures with a wavelength converting plate; and forming a first optical filter on a portion of the wavelength converting plate corresponding to the first light-sensing structure, and a second optical filter on a portion of the wavelength converting plate corresponding to the second light-sensing structure, the first and second optical filters being configured to selectively transmit light in first and second different wavelength ranges, respectively.
The present invention is based upon the realization that an improved spectrum detector, especially suitable for detecting a spectral distribution in the UV-range, can be achieved by using a single wavelength converting plate for covering the different light- sensing structures in the spectrum detector and forming optical filters on the wavelength converting plate for selecting the wavelength range to be sensed by the different light-sensing structures. The spectrum of the incident light can then be determined by combining the outputs of the first and second light-sensing structures. By providing additional light-sensing structures and corresponding additional optical filters, the spectrum can be determined with a higher resolution.
This reduces the number of manufacturing steps compared to the prior art, especially when a larger number of light-sensing structures are utilized. Instead of attaching a different luminescent material layer to each light-sensing structure, differently tuned filters can be manufactured through conventional deposition techniques, and an entire semiconductor (such as silicon) wafer including a large number of spectrum detectors can be processed simultaneously. Furthermore, the differently tuned optical filters can be made very small and can be formed very close to each other, which enables efficient production of a large number of small, high resolution and cost-efficient spectrum detectors suitable for spectrum detection in the UV-range.
The semiconductor substrate may be made of any suitable semiconductor, in which a light-sensing structure can be formed, including, for example, Si, GaAs, InP, SiC, GaP, TiO2, GaN, AlGaN etc.
The light-sensing structures may, in principle, be any kind of semiconductor structure, which reacts on radiation. Such structures include, for example, "ordinary" diodes, and transistors etc. However, the use of dedicated semiconductor elements, such as photodiodes, CCD-elements, bipolar phototransistors, photosensitive field-effect transistor etc is preferred.
The optical filters are preferably bandpass filters in the form of interference filters, which may be realized by alternating providing several layers of dielectric materials having different refractive indices. The wavelength range transmitted by the filter may then be selected by suitably selecting the thicknesses of the layers. Alternatively, the filter may include transparent metal layers, whereby an improved out-of-band blocking may be achieved as compared to the all-dielectric filters.
For the spectrum detector according to the present invention, an optical filter made of all inorganic materials would be preferable, since organic materials are generally more prone to being degraded when subjected to highly energetic radiation, such as UV-light. It should be noted than many types of optical band-pass filters exist and are well-known to the skilled person.
The optical filters may be formed on the wavelength converting plate after having attached the wavelength converting plate to the semiconductor substrate, or, alternatively, prior to attaching the wavelength converting plate to the semiconductor substrate.
Especially for the simultaneous manufacturing of a large number of spectrum detectors on a wafer, and/or when the pitch between the light-sensing structures is very small, it is preferred to form the optical filters after having attached the wavelength converting plate to the semiconductor substrate, because it is generally easier to align a photo mask to structures on the semiconductor substrate than to align a plate to be attached thereto.
The method according to the present invention may further comprise the step of forming a cavity in the wavelength converting plate between the first and second portions thereof to prevent light generated in the first portion from reaching the second light-sensing structure and vice versa. For the same reason, moreover, the method may further include the step of forming a barrier in the semiconductor substrate between the light-sensing structures formed therein.
This barrier may, for example, be formed by etching the semiconductor substrate so that recesses are formed therein, and subsequently building the light-sensing structures in the recesses. The etching may be performed through isotropic etching using, for example, CF4 etch (dry etch) or a mixture of HydroFluoric Acid (HF), Nitric Acid (HNO3) and acetic acid (CH3COOH), or through anisotropic etching using, for example, KOH.
According to another aspect of the present invention, the above-mentioned and other objects are achieved through a spectrum detector, for enabling determination of a spectral distribution in the UV-range, comprising a semiconductor substrate having first and second light-sensing structures formed therein; a first part of a wavelength converting plate covering the first light-sensing structure, and a first optical filter provided on the first part of the wavelength converting plate; and a second part of the wavelength converting plate covering the second light-sensing structure, and a second optical filter provided on the second part of the wavelength converting plate, wherein the first optical filter is configured to selectively transmit light in a first wavelength range, and the second optical filter is configured to selectively transmit light in a second wavelength range, the second wavelength range being different from the first wavelength range. The wavelength converting plate may advantageously be a ceramic plate having a wavelength-converting agent embedded therein.
Hereby, the stability over time of the spectrum detector can be improved, since the ceramic does not degrade even when exposed to the highly energetic UV-light. Furthermore, a ceramic plate can be treated, for example polished, to achieve a sufficiently smooth surface for enabling formation of optical filters directly thereon.
Advantageously, moreover, each of the optical filters may be configured to reflect light being generated in the wavelength converting plate.
Hereby, the efficiency and accuracy of the spectrum detector can be further increased, since it is ensured that practically every photon generated in the wavelength converting plate reaches the relevant light-sensing structure.
In order to prevent photons intended for one light-sensing structure from reaching another light-sensing structure, the spectrum detector according to the invention may further comprise a shielding structure between the first and second light-sensing structures. The shielding structure may advantageously be formed as a wall in the semiconductor substrate. Such a wall can, for example, be achieved by forming recesses in the semiconductor substrate before fabricating the light-sensing structures in the recesses. As a result thereof, the light-sensing structures are shielded from light intended for adjacent light-sensing structures. According to one embodiment of the spectrum detector according to the present invention, each of the first and second parts of the wavelength converting plate may be included in an integral wavelength converting plate. This may typically be the case when the above-mentioned light-shielding structures are comprised in the spectrum detector, or when the spacing between the light-sensing structures is sufficiently large in relation to the extension of the light-sensing structures to keep the cross-talk, or leakage of light between neighboring spectrum detector "pixels", at an acceptably low level.
According to another embodiment, the first and second parts of the wavelength converting plate may be separated from each other, in order to reduce or eliminate cross-talk between neighboring spectrum detector "pixels". Preferably, the gap between the first and second parts of the wavelength converting plate may be filled with a substance, such as air, having a lower refractive index than the wavelength converting plate, such that total internal reflection occurs at the interface between the wavelength converting plate part and the gap. Alternatively, a reflective material, such as a metal, may be deposited on the surface of the wavelength converting plate part facing the gap between the first and second parts.
Advantageously, moreover, the spectrum detector according to the present invention may comprise a number of spectrum detector "pixels" which is larger than two. Each pixel comprises, as described above, a light-sensing structure formed in a semiconductor substrate, a wavelength converting plate part provided on top of the sensing structure to convert light having a short wavelength impinging on the wavelength converting plate part to light having a longer wavelength, which is more suitable for the light-sensing structure, leading to a higher efficiency and increased stability of the light-sensing structure. On top of the wavelength converting plate part is provided an optical filter which prevents light outside a selected wavelength range from passing through it and hitting the wavelength converting plate part. By configuring the optical filters for the different pixels in such a way that they selectively transmit light in different wavelength ranges, a spectrum of the light hitting the spectrum detector can be formed by combining the outputs from the different light-sensing structures. BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the present invention will now be described in more detail, with reference to the appended drawings showing a currently preferred embodiment of the invention, wherein: Fig. Ia is a schematic cross-section view of a spectrum detector according to an embodiment of the present invention;
Fig. Ib is an enlarged view of a portion of the spectrum detector in fig. Ia;
Fig. Ic is a diagram schematically illustrating the frequency selection of the filters comprised in the spectrum detector in fig. Ia; Fig. Id is a diagram schematically illustrating the frequency conversion occurring in the spectrum detector in fig. Ia;
Fig. 2 is a flow chart schematically illustrating a method for manufacturing a spectrum detector according to an embodiment of the present invention;
Figs. 3a-d schematically illustrates the state of the spectrum detector after the corresponding method steps in fig. 2;
Fig. 4 is a cross-section view schematically illustrating another embodiment of the spectrum detector according to the invention, where light-shielding structures are provided between the light-sensing structures; and
Fig. 5 is a cross-section view schematically illustrating a further embodiment of the spectrum detector according to the invention, where gaps have been formed between the light-sensing structures in order to prevent cross-talk.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION
In the following description, the present invention is mainly described with reference to a spectrum detector comprising a photodiode array formed on a silicon substrate, a luminescent ceramic plate, and non-organic interference filters. It should be noted that this by no means limits the scope of the present invention, which is equally applicable to spectrum detectors based on other semiconductors and having other types of wavelength converting plates and/or optical filters. Figs, la-b schematically illustrate a portion of a spectrum detector 1 according to the present invention having three light-sensing structures in the form of photodiodes 2a-c formed in a semiconductor substrate 6.
The spectrum detector 1 further comprises a luminescent ceramic plate 3 covering the photodiodes 2a-c and optical interference filters 4a-c provided on top of the luminescent plate 3 so that incoming light (illustrated by the arrows in Fig. Ia) generally needs to pass through the optical filters 4a-c before reaching the luminescent plate 3. With reference to fig. Ib, which is an enlargement of the portion of the spectrum detector 1 indicated in fig. Ia, it is schematically illustrated how a relatively narrow wavelength range, centered around the wavelength X1 , is permitted to pass through the filter 4a, while the remainder of the incoming light is reflected as indicated by the turning arrows in Fig. Ib. Following passage through the optical filter 4a, the light, generally having a wavelength of λi, hits a wavelength converting substance embedded in the ceramic. An exemplary position of this wavelength converting substance is indicated by an x in Fig. Ib. At location x, the wavelength converting substance (for example phosphor) absorbs the light having wavelength X1, transitions to a more energetic state, and subsequently relaxes back to its ground state and emits light having a wavelength XL in the process. The luminescent ceramic 3 is selected to convert incoming light having a short wavelength, for example in the UV-range, to light in a wavelength XL, which is more suitable for the photodiode 2a. In order to prevent degradation of the photodiodes 2a-c, the wavelength XL converted to may typically be larger than 600 nm for a silicon photodiode.
As is also illustrated in fig. Ib, the light generated in the luminescent ceramic plate 3 at the exemplary location x may be emitted Omni directionally as indicated by the rays 5a-c emanating from the location x. The rays 5a-b generally directed towards the photodiode 2a will hit the photodiode 2a and contribute to the signal output by the photodiode 2a, and the rays 5c-d directed away from the photodiode 2a are, as illustrated in Fig. Ib, reflected in the optical filter 4a and redirected towards the photodiode 2a. In this way, it is ensured that practically all of the converted light finds its way to the photodiode 2a, thereby ensuring that the output from the photodiode as closely as possible corresponds to the fraction of the incident light that is allowed to pass through the optical filter 4a.
By selecting different filters 4a-c permitting passage of different and relatively distinct wavelength ranges centered around X1, X2, and X3, respectively, the outputs from the respective photodiodes 2a-c can be used to determine the spectrum of the incoming light. This is schematically illustrated in Fig. Ic, where a typical relation between the spectrum 10 of the incoming light and the wavelength ranges 11-13 permitted to pass through the optical filters 4a-c, respectively, is shown.
As is evident from fig. Ic, it is preferable to select filters having relatively narrow bands and small out-of-band transmittance. Such filters may advantageously be made by providing a number of layer pairs each including a transparent metal layer and a dielectric layer on top of the luminescent plate 3 on a portion thereof corresponding to a photodiode 2a- c. The transmittance band of such a filter can, as is well known to the skilled person, typically be made narrower by suitably selecting the number of layer pairs and the thickness of the metal and the dielectric layer, respectively. As should be evident from what is described above, the amount of light reaching the luminescent plate 3 depends on the spectrum 10 of the incoming light and the transmittance bands 11-13 of the optical filters 4a-c, respectively. Before reaching the respective photo-diodes 2a-c and thus contributing to the output of the spectrum detector 1, the light is converted in the luminescent plate 3. In Fig. Id, such a wavelength conversion is schematically illustrated for the photodiode 2a - luminescent plate 3 - optical filter 4a - stack of Fig. Ib.
In fig. Id, the spectrum 15 of light absorbed in the luminescent plate 3 in the portion thereof corresponding to the photodiode 2a is shown as the section between the incoming spectrum 10 and the transmittance band 11 for the optical filter 4a. This light is absorbed by the luminescent plate 3 and re-emitted as converted light 16 having a center frequency of λL.
It should here be noted that the situation described above and illustrated by Figs, la-d is simplified in order not to obscure the present invention in details already well known to the skilled person. For example, although the optical filters 4a-c are generally multi-layer filters, they have been illustrated as single layers in Figs. la-b. Furthermore, tuning a number of filters to different wavelengths typically means that the filters have different thicknesses. This has not been specifically illustrated in Figs. la-b. Moreover, as is self-evident to the skilled person, the figures are not drawn to scale, and the structure of the photodiodes 2a-c is not shown in detail. Finally, it should also be noted that the spectra illustrated in Figs, lc-d are exemplary illustrations only.
In this context, it should also be mentioned that although the wavelength conversion per se improves the stability of the photodiodes 2a-c, the luminescent plate 3 and the optical filters 4a-c should also preferably be made as stable as possible with respect to energetic radiation, such as UV-light. This may advantageously be achieved by providing the luminescent plate as a stable ceramic-based plate, and the optical filters as interference filters which are free from organic materials.
For example, the optical filters 4a-c can be manufactured by alternating layers of different dielectrics, or dielectrics and metals, such as SiN, SiO, AI2O3, CaF2, BaF2, Ag, Al, Au etc. Many variations exist as is apparent to the skilled person. Fig. 2 and figs. 3a-c illustrate a method for manufacturing a spectrum detector according to an embodiment of the present invention.
With reference to fig. 2 and fig. 3a, a silicon wafer comprising a plurality of photodiode arrays is provided in a first step 100. The exemplary wafer 30 shown in fig. 3a will eventually be separated into a plurality of individual spectrum detector components.
Each such spectrum detector is represented by a square on the wafer 30, and each such square comprises an array of photodiodes, which is each indicated by a circle in fig. 3a. Considering two neighboring spectrum detectors 31, 32 to be, these are, as shown in the enlarged part of fig. 3a, separated by a so-called scribe lane 33. In the following, the manufacturing of the spectrum detector 32 will be described with reference to the two photodiodes 35a-b in the spectrum detector 32 closest to the scribe lane 33.
Moving on to the next step 101, a luminescent ceramic plate 3 is attached to the wafer by means of an optical bonding material 39. Typically, no other planarization is required, but the luminescent ceramic plate 3 can be attached directly to the top surface 36 of the wafer 30. The luminescent ceramic plate 3 can be pre-polished, or can be polished following attachment to the wafer 30 to be sufficiently smooth to enable forming high quality interference filters directly on the plate 3.
With reference to fig. 3c and continued reference to fig. 2, the interference filters for selecting different wavelength ranges in the incoming light are formed in step 102. These interference filters can be formed through various conventional methods, one of which is described herein. Each spectrum detector 31, 32 on the wafer 30 has a number of photodiodes. Typically, these spectrum detectors 31, 32 are manufactured to be identical to each other. They then each have a number of photodiodes 35a-b which should have different optical filters. However, one or several photodiodes in each of the spectrum detectors should have identical optical filters. In a wafer process, the wafer can first be masked for formation of the first layer on the first photodiodes (one or several corresponding photodiodes in each spectrum detector), and then be masked for formation of the first layer on the second photodiodes (one or several corresponding photodiodes in each spectrum detector), etc. Although requiring several process steps, these are all performed on the wafer scale so that a large number of spectrum detectors can be processed simultaneously. In Fig. 3c, the first layer 37 of the interference filter 38a for the photodiode 35a is shown.
After having processed all the optical filters for all of the photodiodes on the wafer 30, the method finally proceeds to step 103, where the wafer is divided to form separate finished spectrum detector components 31, 32. This is schematically illustrated in
Fig. 3d.
It should be noted that the step 102 of forming the interference filters may be performed before the step 101 of attaching the luminescent ceramic plate 3 to the wafer. As described above, the positions of the interference filters 38a should correspond to the positions of the photodiodes 35 a. Furthermore, in this case, the luminescent ceramic plate having the pre-formed interference filters 38a should be aligned with respect to the photodiodes 35a prior to attachment.
Figs. 4 and 5 schematically illustrate two exemplary embodiments of the spectrum detector according to the invention, in which different measures have been implemented for reducing the occurrence of so-called cross-talk between neighboring photodiodes.
With reference first to fig. 4, a spectrum detector 45 is shown comprising a semiconductor substrate 6, in which five photodiodes 35a-e are formed. As shown in fig. 3d, the spectrum detector 45 in fig. 4 further includes an optical bond layer 39, a luminescent ceramic plate 3 and one optical filter 38a-e for each photodiode 35a-e.
However, the spectrum detector 45 in fig. 4 differs from that shown in fig. 3d in that each photodiode 35a-e is surrounded by a barrier 46 (indicated between the photodiodes 35a and 35b) formed in the semiconductor substrate 6. Through this "dam" structure, each photodiode 35a-e is substantially shielded from light generated in a portion of the luminescent plate 3 above a neighboring photodiode 35a-e.
Turning now to fig. 5, an alternative or complementary configuration for reducing/eliminating cross-talk between neighboring photodiodes 35a-e will be described.
In fig. 5, another exemplary spectrum detector 50 is schematically illustrated, which differs from that shown in Fig. 3d in that the additional process step of removing parts of the luminescent plate 3 between photodiodes 35a-e has been implemented. Hereby, gaps 51a-d between neighboring photodiodes 35a-e are formed. Through a suitable selection of material filling the gaps (air or another substance having a lower refractive index than the luminescent plate) light intended for a particular photodiode 35a-e can be largely confined within the part of the luminescent plate 3 corresponding to that photodiode. This is schematically illustrated for the photodiode 35a in fig. 5 where a ray 52 which is generated in the luminescent plate 3 is first reflected in the optical filter 38a and then at the interface to the gap 51a before reaching the photodiode 35a where it correctly contributes to the output of the spectrum detector 50.

Claims

CLAIMS:
1. A method for manufacturing a spectrum detector (1; 32; 45; 50), for enabling determination of a spectral distribution in the UV-range, comprising the steps of: providing (100) a semiconductor substrate (6) having first (2a; 35 a) and second (2b; 35b) light-sensing structures formed therein; covering (101) said first (2a; 35a) and second (2b; 35b) light-sensing structures with a wavelength converting plate (3); and forming a first optical filter (4a; 38a) on a portion of said wavelength converting plate (3) corresponding to said first light-sensing structure (2a; 35a), and a second optical filter (4b; 38b) on a portion of said wavelength converting plate (3) corresponding to said second light-sensing structure (2b; 35b), said first (4a; 38a) and second (4b; 38b) optical filters being configured to selectively transmit light in first (11) and second (12) different wavelength ranges, respectively.
2. A method according to claim 1, wherein said step of covering comprises the step of: attaching said wavelength converting plate (3) to said semiconductor substrate (6) by means of an optically transparent bonding material (39).
3. A method according to any one of the preceding claims, further comprising the step of: forming a cavity (51a-d) in said wavelength converting plate (3) between said first and second portions thereof to prevent light generated in said first portion from reaching said second light-sensing structure (2b; 35b) and vice versa.
4. A method according to any one of the preceding claims, further comprising the step of: forming a barrier (46) in said semiconductor substrate between the light- sensing structures (2a-b; 35a-b) formed therein to prevent light generated in said first portion from reaching said second light-sensing structure (2b; 35b) and vice versa..
5. A spectrum detector (1; 32; 45; 50), for enabling determination of a spectral distribution in the UV-range, comprising: a semiconductor substrate (6) having first (2a; 35a) and second (2b; 35b) light- sensing structures formed therein; a first part of a wavelength converting plate (3) covering said first light- sensing structure (2a; 35a), and a first optical filter (4a; 38a) provided on said first part of the wavelength converting plate (3); and a second part of a wavelength converting plate (3) covering said second light- sensing structure (2b; 35b), and a second optical filter (4b; 38b) provided on said second part of the wavelength converting plate (3), wherein said first optical filter (4a; 38a) is configured to selectively transmit light in a first wavelength range (11), and said second optical filter (4b; 38b) is configured to selectively transmit light in a second wavelength range (12), said second wavelength range (12) being different from said first wavelength range (11).
6. A spectrum detector (1; 32; 45; 50) according to claim 5, wherein said wavelength converting plate (3) is a ceramic plate having a wavelength converting agent embedded therein.
7. A spectrum detector (1; 32; 45; 50) according to claim 5 or 6, wherein each of said optical filters (4a-c; 38a-e) is configured to reflect light (5c-d) being generated in the wavelength converting plate (3).
8. A spectrum detector (45) according to any one of claims 5 to 7, further comprising a shielding structure (46) provided between said first (2a; 35 a) and second (2b; 35b) light-sensing structures.
9. A spectrum detector (45) according to claim 8, wherein said shielding structure is formed as a wall (46) in said semiconductor substrate (6).
10. A spectrum detector (1; 32; 45) according to any one of claims 5 to 9, wherein said first and second parts of the wavelength converting plate (3) are included in an integral wavelength converting plate (3).
11. A spectrum detector (50) according to any one of claims 5 to 9, wherein said first and second parts of the wavelength converting plate (3) are separated from each other.
12. A spectrum detector (1; 32; 45; 50) according to any one of claims 5 to 11, comprising a semiconductor substrate (6) having an array of light-sensing structures (2a-c; 35a-e) formed therein; a plurality of wavelength converting plate parts, each covering a corresponding one of said light-sensing structures (2a-c; 35a-e); and a plurality of optical filters (4a-c; 38a-e), each being provided on a corresponding one of said wavelength converting plate parts, and each being configured to selectively transmit light having a selected wavelength range (11-13), said wavelength range being different for the different optical filters (4a-c; 38a-e).
PCT/IB2008/051796 2007-05-10 2008-05-08 Spectrum detector for uv radiation and manufacturing method therefore WO2008139379A2 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP07107928 2007-05-10
EP07107928.9 2007-05-10

Publications (2)

Publication Number Publication Date
WO2008139379A2 true WO2008139379A2 (en) 2008-11-20
WO2008139379A3 WO2008139379A3 (en) 2009-01-08

Family

ID=39791466

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/IB2008/051796 WO2008139379A2 (en) 2007-05-10 2008-05-08 Spectrum detector for uv radiation and manufacturing method therefore

Country Status (2)

Country Link
TW (1) TW200915551A (en)
WO (1) WO2008139379A2 (en)

Families Citing this family (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8269985B2 (en) * 2009-05-26 2012-09-18 Zena Technologies, Inc. Determination of optimal diameters for nanowires
US9082673B2 (en) 2009-10-05 2015-07-14 Zena Technologies, Inc. Passivated upstanding nanostructures and methods of making the same
US8889455B2 (en) 2009-12-08 2014-11-18 Zena Technologies, Inc. Manufacturing nanowire photo-detector grown on a back-side illuminated image sensor
US9478685B2 (en) 2014-06-23 2016-10-25 Zena Technologies, Inc. Vertical pillar structured infrared detector and fabrication method for the same
US8519379B2 (en) 2009-12-08 2013-08-27 Zena Technologies, Inc. Nanowire structured photodiode with a surrounding epitaxially grown P or N layer
US8274039B2 (en) 2008-11-13 2012-09-25 Zena Technologies, Inc. Vertical waveguides with various functionality on integrated circuits
US9406709B2 (en) 2010-06-22 2016-08-02 President And Fellows Of Harvard College Methods for fabricating and using nanowires
US9515218B2 (en) 2008-09-04 2016-12-06 Zena Technologies, Inc. Vertical pillar structured photovoltaic devices with mirrors and optical claddings
US9000353B2 (en) 2010-06-22 2015-04-07 President And Fellows Of Harvard College Light absorption and filtering properties of vertically oriented semiconductor nano wires
US8229255B2 (en) 2008-09-04 2012-07-24 Zena Technologies, Inc. Optical waveguides in image sensors
US8890271B2 (en) 2010-06-30 2014-11-18 Zena Technologies, Inc. Silicon nitride light pipes for image sensors
US9299866B2 (en) 2010-12-30 2016-03-29 Zena Technologies, Inc. Nanowire array based solar energy harvesting device
US8791470B2 (en) 2009-10-05 2014-07-29 Zena Technologies, Inc. Nano structured LEDs
US8748799B2 (en) 2010-12-14 2014-06-10 Zena Technologies, Inc. Full color single pixel including doublet or quadruplet si nanowires for image sensors
US9343490B2 (en) 2013-08-09 2016-05-17 Zena Technologies, Inc. Nanowire structured color filter arrays and fabrication method of the same
US8299472B2 (en) 2009-12-08 2012-10-30 Young-June Yu Active pixel sensor with nanowire structured photodetectors
US8866065B2 (en) 2010-12-13 2014-10-21 Zena Technologies, Inc. Nanowire arrays comprising fluorescent nanowires
US8735797B2 (en) 2009-12-08 2014-05-27 Zena Technologies, Inc. Nanowire photo-detector grown on a back-side illuminated image sensor
US8835831B2 (en) 2010-06-22 2014-09-16 Zena Technologies, Inc. Polarized light detecting device and fabrication methods of the same
US8546742B2 (en) 2009-06-04 2013-10-01 Zena Technologies, Inc. Array of nanowires in a single cavity with anti-reflective coating on substrate

Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4822998A (en) * 1986-05-15 1989-04-18 Minolta Camera Kabushiki Kaisha Spectral sensor with interference filter
US5001532A (en) * 1989-09-06 1991-03-19 Rockwell International Corporation Impurity band conduction detector having photoluminescent layer
US5227648A (en) * 1991-12-03 1993-07-13 Woo Jong Chun Resonance cavity photodiode array resolving wavelength and spectrum
FR2697352A1 (en) * 1992-10-26 1994-04-29 Physique Rayon Lumie Lab Electromagnetic energy concentrator with frequency shift - uses dopant that responds to electromagnetic excitation by emitting light at different frequency
US5574286A (en) * 1995-06-30 1996-11-12 Huston; Alan L. Solar-blind radiation detector
US5784507A (en) * 1991-04-05 1998-07-21 Holm-Kennedy; James W. Integrated optical wavelength discrimination devices and methods for fabricating same
DE19723234A1 (en) * 1997-06-03 1998-12-10 Siemens Ag Filters for filtering out spectral ranges and optical system for combustion analysis
FR2765970A1 (en) * 1997-07-11 1999-01-15 Commissariat Energie Atomique METHOD FOR MANUFACTURING AN OPTICAL FILTER MATRIX, OPTICAL FILTER MATRIX AND SPECTROMETRY DEVICE USING SUCH A MATRIX
US6005252A (en) * 1996-01-11 1999-12-21 The Trustees Of Princeton University Method and apparatus for measuring film spectral properties
WO2000074140A1 (en) * 1999-06-02 2000-12-07 Intel Corporation Image sensor response enhancement using fluorescent phosphors
EP1239270A1 (en) * 2001-02-21 2002-09-11 Horiba, Ltd. Optical detector
US20040239939A1 (en) * 2003-05-28 2004-12-02 Onera Stationary fourier transform spectrometer
US20070145236A1 (en) * 2005-12-22 2007-06-28 Palo Alto Research Center Incorporated Photosensing throughout energy range and in subranges
DE102006039071A1 (en) * 2006-08-09 2008-02-21 Universität Kassel Making optical filter array with two distributed Bragg reflectors and intervening Fabry Perot filter elements, employs nano-imprint procedure to form differentiated filter cavities

Patent Citations (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4822998A (en) * 1986-05-15 1989-04-18 Minolta Camera Kabushiki Kaisha Spectral sensor with interference filter
US5001532A (en) * 1989-09-06 1991-03-19 Rockwell International Corporation Impurity band conduction detector having photoluminescent layer
US5784507A (en) * 1991-04-05 1998-07-21 Holm-Kennedy; James W. Integrated optical wavelength discrimination devices and methods for fabricating same
US5227648A (en) * 1991-12-03 1993-07-13 Woo Jong Chun Resonance cavity photodiode array resolving wavelength and spectrum
FR2697352A1 (en) * 1992-10-26 1994-04-29 Physique Rayon Lumie Lab Electromagnetic energy concentrator with frequency shift - uses dopant that responds to electromagnetic excitation by emitting light at different frequency
US5574286A (en) * 1995-06-30 1996-11-12 Huston; Alan L. Solar-blind radiation detector
US6005252A (en) * 1996-01-11 1999-12-21 The Trustees Of Princeton University Method and apparatus for measuring film spectral properties
DE19723234A1 (en) * 1997-06-03 1998-12-10 Siemens Ag Filters for filtering out spectral ranges and optical system for combustion analysis
FR2765970A1 (en) * 1997-07-11 1999-01-15 Commissariat Energie Atomique METHOD FOR MANUFACTURING AN OPTICAL FILTER MATRIX, OPTICAL FILTER MATRIX AND SPECTROMETRY DEVICE USING SUCH A MATRIX
WO2000074140A1 (en) * 1999-06-02 2000-12-07 Intel Corporation Image sensor response enhancement using fluorescent phosphors
EP1239270A1 (en) * 2001-02-21 2002-09-11 Horiba, Ltd. Optical detector
US20040239939A1 (en) * 2003-05-28 2004-12-02 Onera Stationary fourier transform spectrometer
US20070145236A1 (en) * 2005-12-22 2007-06-28 Palo Alto Research Center Incorporated Photosensing throughout energy range and in subranges
DE102006039071A1 (en) * 2006-08-09 2008-02-21 Universität Kassel Making optical filter array with two distributed Bragg reflectors and intervening Fabry Perot filter elements, employs nano-imprint procedure to form differentiated filter cavities

Also Published As

Publication number Publication date
TW200915551A (en) 2009-04-01
WO2008139379A3 (en) 2009-01-08

Similar Documents

Publication Publication Date Title
WO2008139379A2 (en) Spectrum detector for uv radiation and manufacturing method therefore
US11929382B2 (en) Shallow trench textured regions and associated methods
US8736006B1 (en) Backside structure for a BSI image sensor device
US9478575B2 (en) Solid-state image sensor
US7262404B2 (en) Photodetector manufacturable by semiconductor processes
JP4723860B2 (en) CMOS image sensor
US9129874B1 (en) Light sensor having IR cut interference filter with color filter integrated on-chip
KR101891342B1 (en) Imaging device and imaging apparatus
TWI809074B (en) Multi-spectral light sensor
JP6631243B2 (en) Solid-state imaging device and optical filter
JP3003597B2 (en) Solid-state imaging device
EP3550606B1 (en) Solid-state imaging element
JPH0745805A (en) Solid-stage image pickup device
US20210280625A1 (en) Image sensor
JP2021509544A (en) Semiconductor optical sensor for detecting visible light and ultraviolet light and its manufacturing process
US20140374863A1 (en) Image pickup apparatus, method of designing the same, and method of manufacturing the same
CN108258002B (en) Semiconductor device and method for manufacturing the same
US20020063214A1 (en) Optoelectronic microelectronic fabrication with infrared filter and method for fabrication thereof
US20200075651A1 (en) Double-layer color filter and method for forming the same
WO2013111419A1 (en) Solid-state image pickup apparatus
WO2022190732A1 (en) Photodetector element
KR100907892B1 (en) Image sensor and its manufacturing method
US20240055456A1 (en) Solid-state imaging device
JP6654067B2 (en) Optical sensor
KR101220143B1 (en) One-chip semiconductor apparatus for photo detectors with different receiving band and integrated circuit and manufacturing method thereof

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 08751154

Country of ref document: EP

Kind code of ref document: A2

NENP Non-entry into the national phase in:

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 08751154

Country of ref document: EP

Kind code of ref document: A2