Patent ID: 11955430
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method of manufacturing a semiconductor device, comprising:
forming a first dielectric layer over a substrate;
forming a metal layer in the first dielectric layer;
forming an etch stop layer on a surface of the first dielectric layer and the metal layer;
removing portions of the metal layer and the etch stop layer to form a recess in the metal layer, the recess being spaced apart from a bottom surface of the etch stop layer; and
forming a tungsten plug in the recess, wherein the metal layer includes cobalt, and first portions of the metal layer at or near a surface of the metal layer include an oxide of cobalt, and
wherein the method further comprises performing an etching operation using a fluoride containing gas to remove the first portions of the metal layer and remove second portions of the metal layer below the first portions to form the recess.