Elevated pocket pixels, imaging devices and systems including the same and method of forming the same
AssigneeMicron Technology, Inc.
InventorSalman Akram
Life of this patent
Estimating the term…
Abstract
An elevated photosensor for image sensors and methods of forming the photosensor. The photosensor may have light sensors having indentation features including, but not limited to, v-shaped, u-shaped, or other shaped features. Light sensors having such an indentation feature can redirect incident light that is not absorbed by one portion of the photosensor to another portion of the photosensor for additional absorption. In addition, the elevated photosensors reduce the size of the pixel cells while reducing leakage, image lag, and barrier problems.
Claims22
A photosensor comprising:
- an epitaxial doped region having a first conductivity type formed over a doped region of a substrate, wherein the substrate doped region is a second conductivity type;
- a raised photosensitive region comprising a hydrogenated amorphous silicon material formed over the epitaxial doped region and having at least one indentation feature over the epitaxial doped region, wherein the photosensitive region is configured to redirect reflected light;
- and
- an upper electrode overlying the at least one indentation feature of the hydrogenated amorphous silicon material, the upper electrode having a portion through which one portion of the photosensitive region redirects the reflected light to another portion of the photosensitive region.
A photosensor comprising:
- an epitaxial doped region having a first conductivity type formed over a doped region of a substrate, wherein the substrate doped region is a second conductivity type;
- a raised photosensitive region comprising a hydrogenated amorphous silicon material formed over the epitaxial doped region and having at least one indentation feature over the epitaxial doped region, the hydrogenated amorphous silicon material being adapted to redirect reflected light from one portion of the photosensitive region to another portion of the photosensitive region;
- and
- a color filter formed in the at least one indentation feature of the hydrogenated amorphous silicon material.
A method of forming a photosensor comprising the steps of:
- providing a semiconductor substrate having a first doped region of a first conductivity type;
- forming an epitaxial doped region of second conductivity over the first doped region;
- forming a raised photosensitive region over the epitaxial doped region by:
- forming a dielectric over the epitaxial doped region;
- forming at least one trench in the dielectric;
- and
- forming a hydrogenated amorphous silicon material over the dielectric, wherein the hydrogenated amorphous silicon material is contoured to the at least one trench.
A method of forming an imaging device comprising:
- forming each of a plurality of photosensors by:
- forming a first doped region of a first conductivity type in a substrate;
- forming an epitaxial doped region of a second conductivity type over the first doped region;
- forming a dielectric over the epitaxial doped region;
- forming at least one trench in the dielectric to the epitaxial doped region;
- and
- forming a hydrogenated amorphous silicon material over the dielectric and the at least one trench, wherein the hydrogenated amorphous silicon material is contoured to the at least one trench.
Dependencies are inferred from the claim text.