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. 29, 2025
Filed:
May. 24, 2022
Shanghai Huali Integrated Circuit Corporation, Shanghai, CN;
Zhigang Yang, Shanghai, CN;
Heng Liu, Shanghai, CN;
Xiaoying Meng, Shanghai, CN;
Jianghua Leng, Shanghai, CN;
Tianpeng Guan, Shanghai, CN;
Shanghai Huali Integrated Circuit Corporation, Shanghai, CN;
Abstract
A method for making a semi-floating gate transistor with a three-gate structure is disclosed, comprising: forming a first trench structure in isolated active regions and a first polysilicon layer, removing part of the first polysilicon layer; forming a second gate oxide layer and a second polysilicon layer; patterning isolation trench; filling an isolation dielectric layer in the isolation trench; and forming a trench between two first trench structures, to cut open the second polysilicon layer, the second gate oxide layer, the first polysilicon layer and the first gate oxide layer into two parts, so that the active region is exposed from the bottom of the trench, wherein the first polysilicon layer on either side of the trench forms a first gate, and portions of the second polysilicon layer on both sides of the isolation trench form a second gate and a third gate.