Passivation scheme for image sensor substrate
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorKai-Yun Yang
Life of this patent
Estimating the term…
Abstract
The present disclosure relates to an integrated chip including a substrate. A photodetector is arranged within the substrate. A trench isolation structure extends into the substrate on opposite sides of the photodetector. The trench isolation structure separates the photodetector from neighboring photodetectors. A first passivation layer is between a sidewall of the substrate and a sidewall of the trench isolation structure. The first passivation layer includes hydrogenated amorphous silicon.
Claims20
A method for forming an integrated chip, the method comprising:
- forming a photodetector in a substrate;
- patterning the substrate to form a trench in the substrate, wherein the trench is formed by sidewalls of the substrate, and wherein the trench surrounds the photodetector;
- depositing a first passivation layer on the sidewalls of the substrate that form the trench, the first passivation layer comprising hydrogenated amorphous silicon;
- and
- depositing a dielectric layer over the first passivation layer and in a remainder of the trench to form a trench isolation structure over the first passivation layer and surrounding the photodetector.
A method for forming an integrated chip, the method comprising:
- forming a photodetector in a substrate;
- etching the substrate to form a trench in the substrate, wherein the trench surrounds the photodetector and the trench is delimited by sidewalls of the substrate;
- forming a passivation structure along the sidewalls of the substrate, the passivation structure comprising hydrogenated amorphous silicon having p-type doping;
- and
- depositing a dielectric layer over of the passivation structure to from a trench isolation structure in the trench, wherein the trench isolation structure is separated from the substrate by the passivation structure.
A method for forming an integrated chip, the method comprising:
- forming a first semiconductor well having a first doping type in a substrate along a first side of the substrate;
- forming second semiconductor well having a second doping type, different than the first doping type, in the substrate along a second side of the substrate, opposite the first side;
- etching the first side of the substrate to form a trench in the substrate, wherein the trench surrounds a photodetector in the first semiconductor well, wherein the trench is delimited by sidewalls of the substrate and an upper surface of the substrate, and wherein the first semiconductor well extends along the sidewalls of the substrate and the second semiconductor well extends along the upper surface of the substrate;
- depositing a first passivation layer on the sidewalls of the substrate and the upper surface of the substrate, the first passivation layer comprising hydrogenated amorphous silicon;
- and
- depositing a dielectric layer over sidewalls and an upper surface of the first passivation layer to form a trench isolation structure surrounding the photodetector.
Dependencies are inferred from the claim text.