Patent ID: 6472255
Filing Date: 2002-10-29
Classification: H01L

Abstract:
A method for producing a solid-state image pickup device comprising:a charge transfer portion for transferring an electric charge produced in a light receiving portion through photoelectric conversion from an incident light to said electric charge, and an output amplifier portion for detecting said electric charge to issue a signal; wherein said charge transfer portion is provided with a first gate insulation film having a sufficient film thickness to keep a predetermined transfer efficiency, and said output amplifier portion is provided with a second gate insulation film having a film thickness suitable for obtaining a predetermined mutual conductance capable of increasing the gain of said output amplifier portion; the method comprising the steps of: forming an insulation film, in which a multilayer film is formed by stacking a thermal oxidation film, a nitride film, and a first Chemical Vapor Deposition (â€œCVDâ€ ) oxidation film together in the mentioned order in a region where said charge transfer portion and said output amplifier portion are formed on a semiconductor substrate; forming a first layer charge transfer electrode in a region where said charge transfer portion is formed; forming a second CVD oxidation film after all of said first CVD oxidation film, except said first CVD oxidation film immediately underneath said first layer charge transfer electrode, is removed; oxidizing said first layer charge transfer electrode to increase said second CVD oxidation film in film thickness; removing said multilayer film at said region where said output amplifier portion is formed; forming an oxide film serving as a gate insulation film in said region where said output amplifier portion is formed, and simultaneously again oxidizing said first layer charge transfer electrode to increase further said second CVD oxidation film in film thickness; and forming a second layer charge transfer electrode through both said multilayer film and said second CVD oxidation film in said region where said charge transfer portion is formed, and simultaneously forming a gate electrode in said region where said output amplifier portion is formed.