Patent ID: 11961866
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 13:
14. A method of forming an image sensor, the method comprising:
forming a photodiode in a substrate;
depositing a contact etch stop layer (CESL) over the substrate, wherein the CESL is over the photodiode;
forming an interconnect structure over the CESL, wherein the interconnect structure comprises a first dielectric material;
defining an opening, using etching, over the photodiode, wherein the opening exposes a portion of the CESL;
depositing a cap layer along sidewalls and a bottom surface of the opening, wherein the cap layer comprises a second dielectric material having a higher moisture resistance than the first dielectric material; and
forming a gate structure over the photodiode, wherein the gate structure comprises a gate dielectric and a gate electrode, the CESL is over the gate structure, and defining the opening comprises etching into the gate structure.