Semiconductor integrated circuit device

Abstract

Abstract PURPOSE:To decrease the loss due to reflection so as to improve a photodetector element in a property by a method wherein a film, which is composed of a film that is on a substrate side and comprises SiO2 as a main component and a silicon oxynitride film that starts decreasing in a SiN component from the lowest layer, contains only SiO2 at the upper most layer, and overlaps the former film, is made to cover a photodetector section. CONSTITUTION:A FET which is composed of photodiodes of a player 2, a p-t type source/drain 3, a SiO2 film 4, and a gate 5, and a capacitor composed of a p layer 6 and a wiring interposing the SiO2 film 4 between them, are integrated on the surface of an N-type Si substrate 1, and a silicon oxynitride film 8 is provided onto a A wiring 7. A specified amount of SiN and NO2 is made to keep flowing in a reaction vessel which is kept at a pressure of 1 Torr, NH3 is made to flow into the vessel as it decreases at a prescribed flow rate per minute starting from a specified flow rate, and a RF power is applied, so that a silicon oxynitride film 8 is made to be deposited which starts decreasing in a SiN component from the lowest layer. The film 8 starts decreasing continuously in refractive index from the lowest layer toward the uppermost layer and is remarkably lower than a silicon nitride film in refractive index. Therefore, the refractive index of the film 8 is made to decrease remarkably at the interface of it with a SiO2 film or air, so that a photodetector is improved in property.

Inventors

• 👤 Akinori Shimizu

Bibliographic Details