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:
Apr. 23, 2024
Filed:
Nov. 19, 2021
Hua Hong Semiconductor (Wuxi) Limited, Wuxi, CN;
Junwen Liu, Wuxi, CN;
Hua Hong Semiconductor (Wuxi) Limited, Wuxi, CN;
Abstract
A method for making a high-voltage thick gate oxide, which includes depositing a pad silicon oxide on a silicon substrate and depositing a pad silicon nitride on the pad silicon oxide; performing shallow trench isolation photolithography, etching, silicon oxide filling and chemical mechanical polishing; sequentially depositing a mask silicon nitride and a mask silicon oxide on a silicon wafer; removing the mask silicon oxide and the mask silicon nitride in a high-voltage thick gate oxide region, and remaining the pad silicon nitride between two shallow trench isolations in the high-voltage thick gate oxide region; performing first thermal oxidation growth; removing the pad silicon nitride between the two shallow trench isolations in the high-voltage thick gate oxide region; performing second thermal oxidation growth to produce a high-voltage thick gate oxide.