The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 27, 2022
Filed:
Apr. 28, 2021
Shanghai Huali Integrated Circuit Corporation, Shanghai, CN;
Shidong Fu, Shanghai, CN;
Ran Huang, Shanghai, CN;
Bohan Jiang, Shanghai, CN;
Ying Xu, Shanghai, CN;
SHANGHAI HUALI INTEGRATED CIRCUIT CORPORATION, Shanghai, CN;
Abstract
A method for etching back a hard mask layer on top of dummy polysilicon gates in a gate last process comprises: step 1: forming a plurality of dummy gate structures; step 2: depositing a spin-on carbon (SOC) layer to fill the space regions between the sidewalls of the dummy gate structures to a level above the top surface of each of the plurality of dummy gate structures; step 3: performing a first etching-back to the spin-on carbon layer to remove the SOC layer outside the space regions and keep the SOC layer in the space regions below the top surfaces of each of dummy polysilicon gate; step 4: performing a second etching-back by using the remaining spin-on carbon layer as a mask to remove the hard mask layer and the sidewalls of the dummy polysilicon gates on both sides of the hard mask layer at the same time; step 5: removing the SOC layer. This technique saves one photomask and improves the process window.