Method for manufacturing image capturing device and image capturing device
AssigneeRenesas Electronics Corporation
InventorsTakeshi Kamino, Takahiro Tomimatsu
Life of this patent
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Abstract
An offset spacer film (OSS) is formed on a side wall surface of a gate electrode (NLGE, PLGE) to cover a region in which a photo diode (PD) is disposed. Next, an extension region (LNLD, LPLD) is formed using the offset spacer film and the like as an implantation mask. Next, process is provided to remove the offset spacer film covering the region in which the photo diode is disposed. Next, a sidewall insulating film (SWI) is formed on the side wall surface of the gate electrode. Next, a source-drain region (HPDF, LPDF, HNDF, LNDF) is formed using the sidewall insulating film and the like as an implantation mask.
Claims10
A method for manufacturing an image capturing device including a photoelectric conversion region, a transfer transistor and a floating diffusion region, the method comprising the steps of:
- (a) defining a pixel region by forming an element isolation insulating film in a semiconductor substrate;
- (b) forming a transfer gate electrode of said transfer transistor in said pixel region, said transfer gate electrode having a first side surface and a second side surface opposite to said first side surface;
- (c) forming said photoelectric conversion region at a portion of said pixel region on said first side surface side of said transfer gate electrode;
- (d) forming a first insulating film so as to cover said pixel region;
- (e) removing a portion of said first insulating film on said photoelectric conversion region and said first side surface of said transfer gate electrode by performing a wet etching process;
- (f) forming a second insulating film so as to cover said pixel region;
- (g) removing a portion of said first insulating film and a portion of said second insulating film by anisotropic etching while protecting said photoelectric conversion region and said first side surface of said transfer gate electrode;
- wherein in step (g),
- a first sidewall spacer is formed from said second insulating film so as to extend from said first side surface of said transfer gate electrode to said photoelectric conversion region, and
- a second side wall spacer is formed from said first insulating film and said second insulating film so as to cover said second side surface of said transfer gate electrode;
- and
- (h) forming said floating diffusion region in said pixel region on said second side surface side of said transfer gate electrode by implanting an impurity of a predetermined conductivity type using said second sidewall spacer as an implantation mask.
An image capturing device, comprising:
- a pixel region defined by an element isolation insulating film formed in a semiconductor substrate,
- said pixel region including:
- a first pixel region, a second pixel region, and a third pixel region, respectively corresponding to red, green and blue, and each including a photoelectric conversion unit, a transfer transistor, and a floating diffusion region,
- a transfer gate electrode of each transfer transistor having a first side surface and a second side surface opposite to said first side surface,
- each photoelectric conversion region being formed at a portion of the corresponding pixel region on said first side surface side of the corresponding transfer gate electrode, and
- each floating diffusion region being formed at a portion of the corresponding pixel region on said second side surface side of the corresponding transfer gate electrode,
- a respective offset spacer film being formed on said second side surface of each transfer gate electrode;
- a respective sidewall insulating film being formed so as to extend from over said first side surface of each transfer gate electrode to over the corresponding photoelectric conversion region and formed over said second side surface of that transfer gate electrode to cover the corresponding offset spacer film;
- and
- a silicidation blocking film formed to cover said photoelectric conversion region of at least one of said first to third pixel regions.
Dependencies are inferred from the claim text.