A vapor supply apparatus, for use in a semiconductor device manufacturing process, provides a three-dimensional showerhead for supplying various precursors to a reaction chamber. The three-dimensional showerhead comprises an inverted-cup structure having double walls, an outer wall and an inner wall,...http://www.google.co.uk/patents/US6444039?utm_source=gb-gplus-sharePatent US6444039 - Three-dimensional showerhead apparatus
