Patent ID: 11942419
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 14:
15. A method comprising:
forming a first dielectric layer;
forming a second dielectric layer over the first dielectric layer, the forming the second dielectric layer comprising:
forming a first sub layer, with the first sub layer being over and contacting a conductive feature, wherein the first sub layer is free from oxygen;
forming a second sub layer over the first sub layer; and
converting a top portion of the second sub layer into a third sub layer;

depositing a third dielectric layer over and in physical contact with the second dielectric layer;
performing a first etching process to etch-through the third dielectric layer and the third sub layer, wherein the first etching process is stopped by the second sub layer; and
performing a second etching process to etch the second sub layer and the first sub layer.