Patent ID: 11894404
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 10:
11. A method for fabricating an optical structure, comprising:
forming a light detection region in a substrate;
forming an isolation structure surrounding the light detection region; and
forming a primary grid over the isolation structure, comprising:
forming a metal layer over the isolation structure;
forming a first dielectric layer over the metal layer; and
patterning the metal layer and the first dielectric layer;

forming a second dielectric layer over the primary grid;
forming a trench in the second dielectric layer;
forming a filling material in the trench; and
forming a secondary grid at least partially surrounded by the primary grid laterally, comprising:
partially removing the second dielectric layer by patterning, thereby at least a portion of the filling material and a portion of the second dielectric layer below the filling material is remained.