Solid-state imaging element and method for fabricating the same
AssigneePanasonic Corporation
InventorsHiroyuki DOI, Ryohei MIYAGAWA, Hitoshi KURIYAMA
Life of this patent
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Abstract
A solid-state imaging element includes a photodiode formed in an upper portion of a semiconductor substrate to perform a photoelectric conversion, a silicon dioxide film formed on the substrate to cover the photodiode, and a silicon nitride film formed on the silicon dioxide film. The silicon nitride film has a thinner portion smaller in thickness than at least an end portion of the silicon nitride film entirely or partly over the photodiode.
Claims20
A solid-state imaging element comprising:
- a photodiode formed in an upper portion of a semiconductor substrate to perform a photoelectric conversion;
- a first insulating film formed on the semiconductor substrate to cover the photodiode;
- and
- a second insulating film formed on the first insulating film, wherein
- the second insulating film has a thinner portion smaller in thickness than at least an end portion of the second insulating film entirely or partly over the photodiode.
A solid-state imaging element comprising:
- a photodiode formed in an upper portion of a semiconductor substrate to perform a photoelectric conversion;
- a transistor formed in a region of the semiconductor substrate electrically isolated from the photodiode, and having sidewall spacers on side surfaces of a gate electrode thereof;
- a first insulating film formed on the semiconductor substrate to cover the photodiode;
- and
- a second insulating film formed on the first insulating film, wherein
- the sidewall spacers are each made of a multilayer structure of the first and second insulating films formed in order of increasing distance from each of the side surfaces of the gate electrode.
A method for fabricating a solid-state imaging element comprising a photodiode formed in an upper portion of a semiconductor substrate to perform a photoelectric conversion, and a transistor formed in a region of the semiconductor substrate electrically isolated from the photodiode to process a signal photoelectrically converted by the photodiode, the method comprising the steps of:
- (a) forming an isolation region in the semiconductor substrate to electrically isolate a region where the photodiode is formed and a region where the transistor is formed;
- (b) forming the photodiode made of a diffusion layer in the upper portion of the semiconductor substrate in the region where the photodiode is formed, and forming the transistor in the semiconductor substrate in the region where the transistor is formed;
- (c) forming a first insulating film on the semiconductor substrate to cover the photodiode as well as the transistor;
- (d) forming a second insulating film on the first insulating film;
- (e) forming a first resist pattern entirely or partly covering a portion of the second insulating film located over the photodiode;
- (f) etching the first and second insulating films using the first resist pattern as a mask so as to leave the first and second insulating films over the photodiode, while forming sidewall spacers each composed of the first and second insulating films on side surfaces of a gate electrode composing the transistor;
- and
- (g) removing the first resist pattern.
Dependencies are inferred from the claim text.