Patent ID: 11973129
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H  B | IPC H

Claim 15:
16. A method for forming a semiconductor device structure, comprising:
forming a fin structure in which first semiconductor layers and second semiconductor layers are alternatingly stacked;
forming a dummy gate structure across the fin structure;
forming a gate spacer layer alongside the dummy gate structure;
removing the dummy gate structure;
removing the first semiconductor layers to form first gaps;
forming a dielectric layer to fill the first gaps, wherein the gate spacer layer has a first nitrogen concentration, and the dielectric layer has a second nitrogen concentration that is greater than the first nitrogen concentration;
partially treating the dielectric layer to form a treated portion;
removing the treated portion of the dielectric layer to form second gaps; and
forming a gate stack in the second gaps to surround the second semiconductor layers.