CMOS imager pixel designs
AssigneeMicron Technology, Inc.
InventorsHoward Rhodes, Jeff McKee
Life of this patent
Estimating the term…
Abstract
A charge storage capacitor which is connected to various light sensitive and/or electrical elements of a CMOS imager, as well as methods of formation, are disclosed. The charge storage capacitor may be formed entirely over a field oxide region of the CMOS imager, entirely over an active area of a pixel sensor cell, or partially over a field oxide region and partially over an active pixel area of a pixel sensor cell.
Claims121
A photosensor for use in a CMOS imaging device, said photosensor comprising:
- a field oxide region formed in a substrate;
- a doped layer of a first conductivity type formed in said substrate and adjacent said field oxide region;
- a charge collection region formed in said doped layer;
- and
- a charge storage capacitor connected to said charge collection region to store charge accumulated by said charge collection region, said charge storage capacitor overlying said field oxide region.
A photosensor for use in an imaging device formed in a single integrated circuit, said photosensor comprising:
- a doped layer of a first conductivity type formed in a substrate;
- a charge collection region formed in said doped layer;
- a floating diffusion region for receiving charge from said charge collection region;
- and
- a charge storage capacitor electrically connected to said floating diffusion region, said charge storage capacitor being formed at least partially over one of a field oxide region and an active area of said photosensor.
A photosensor for use in an imaging device, said photosensor comprising:
- a field oxide region formed in a substrate;
- a doped layer of a first conductivity type formed in said substrate and adjacent said field oxide region;
- a charge collection region formed in said doped layer;
- a first doped region of a second conductivity type formed in said doped layer adjacent said charge collection region;
- and
- a first storage capacitor formed over said substrate adjacent said first doped region and connected to said first doped region to store charge collected in said charge collection region, said storage capacitor being formed at least partially over at least one of said field oxide region and an active area of said photosensor;
- a transferred charge region for receiving charge from said charge collection region;
- and
- a second storage capacitor connected to said transferred charge region.
A CMOS imager system comprising:
- (i) a processor;
- and
- (ii) a CMOS imaging device coupled to said processor, said CMOS imaging device comprising:
- a doped layer of a first conductivity type formed in a substrate and adjacent a field oxide region;
- a charge collection region formed in said doped layer;
- a first doped region of a second conductivity type formed in said doped layer adjacent said charge collection region;
- and
- a charge storage capacitor formed entirely over said field oxide region.
A method of forming a CMOS imager having improved charge storage comprising the steps of:
- providing a semiconductor substrate having a doped layer of a first conductivity type;
- forming a first doped region of a second conductivity type in said doped layer, said first doped region being adjacent a field oxide region;
- forming a charge storage capacitor overlying entirely over at least one of said field oxide region and an active area of said CMOS imager;
- and
- forming a contact between said first doped region and said charge storage capacitor.
A method of forming a CMOS imager having improved charge storage comprising the steps of:
- providing a semiconductor substrate having a doped layer of a first conductivity type;
- forming a field oxide region within said semiconductor substrate;
- forming a first conductive layer over said field oxide region and said substrate;
- forming an insulating layer over said first conductive layer;
- forming a second conductive layer over said insulating layer;
- patterning said first conductive layer, said insulating layer and said second conductive layer to form a storage capacitor and an electrical element of said CMOS imager, wherein said storage capacitor is formed entirely over and in contact with said field oxide region.
Dependencies are inferred from the claim text.