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:
Mar. 09, 2021
Filed:
Dec. 06, 2019
Shanghai Huahong Grace Semiconductor Manufacturing Corporation, Shanghai, CN;
Abstract
A manufacturing method for a shielded gate trench device comprises the following steps: Stepforming a gate trench in a first epitaxial layer; Stepforming a first dielectric layer and fully filling the gate trench with a first polysilicon layer; Stepforming a top trench: Stepcarrying out primary polysilicon dry-etching; Stepcarrying out primary dielectric layer wet-etching to decrease the thickness of the first dielectric layer in the top trench; Stepcarrying out secondary polysilicon dry-etching; Stepcarrying out secondary dielectric layer wet-etching to remove the rest of the first dielectric layer on a side face of the top trench and to form the top trench; and Stepforming a trench gate in the top trench. By adoption of the manufacturing method, the gate-source capacitance and the gate-drain capacitance can be decreased, and thus, the input capacitance is decreased.