Patent ID: 11935795
Assignee: TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY LTD.
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method for forming a semiconductor device, comprising:
depositing a protective coating on a first polysilicon layer in a first transistor;
forming an epitaxial layer on the protective coating for a second transistor; and
depositing a second polysilicon layer over the epitaxial layer for the second transistor,
wherein the protective coating comprises a first dielectric layer and a third polysilicon layer, wherein the third polysilicon layer is deposited at a first temperature in a range of 600-700 degree Celsius, and wherein the third polysilicon layer in the protect coating is configured to protect the first polysilicon layer of the first transistor when the second transistor is formed.