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:
Jul. 16, 2024
Filed:
Apr. 06, 2022
United Semiconductor (Xiamen) Co., Ltd., Fujian, CN;
Sen Mao Feng, Fujian, CN;
Ming Xuan Ren, Fujian, CN;
Shih-Hsien Huang, Kaohsiung, TW;
Wen Yi Tan, Fujian, CN;
United Semiconductor (Xiamen) Co., Ltd., Fujian, CN;
Abstract
A method of removing a hard mask layer includes providing a gate. A hard mask layer covers and contacts a top surface of the gate. Two spacer structures respectively contacts two sides of the gate. Two first spacers are respectively disposed on the two spacer structures. Later, a wet etching process is performed to remove the hard mask layer and the first spacers and keep the spacer structures. An etchant is utilized in the wet etching process. A selective etching ratio of the silicon nitride to silicon oxide of the etchant is more than 90. The etchant includes Si(OH). A concentration of Si(OH). is greater than or equal to 3.95 ppm and smaller than or equal to 10 ppm.