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:
Feb. 18, 2020
Filed:
Aug. 02, 2018
Renesas Electronics Corporation, Tokyo, JP;
Yasuhiro Okamoto, Ibaraki, JP;
Takashi Ide, Ibaraki, JP;
Renesas Electronics Corporation, Tokyo, JP;
Abstract
Characteristics of a semiconductor device are improved. A method of manufacturing a semiconductor device of the invention includes a step of forming a gate insulating film over a nitride semiconductor layer. The step includes steps of forming a crystalline AlOfilm on the nitride semiconductor layer, forming a SiOfilm on the AlOfilm, and forming an amorphous AlOfilm on the SiOfilm. The step further includes steps of performing heat treatment on the amorphous AlOto crystallize the amorphous AlO, thereby forming a crystalline AlOfilm, and forming a SiOfilm on the crystalline AlOfilm. In this way, since a film stack, which is formed by alternately stacking the crystalline AlOfilms and the SiOfilms from a bottom side, is used as the gate insulating film, threshold voltage can be cumulatively increased.