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. 10, 2020
Filed:
Feb. 26, 2016
Sanken Electric Co., Ltd., Niiza-shi, Saitama, JP;
Shin-etsu Handotai Co., Ltd., Tokyo, JP;
Hiroshi Shikauchi, Niiza, JP;
Ken Sato, Miyoshi-machi, JP;
Masaru Shinomiya, Annaka, JP;
Keitaro Tsuchiya, Takasaki, JP;
Kazunori Hagimoto, Takasaki, JP;
SANKEN ELECTRIC CO., LTD., Niiza, JP;
SHIN-ETSU HANDOTAI CO., LTD., Tokyo, JP;
Abstract
Semiconductor base including: silicon-based substrate; buffer layer including first and second layers alternately on silicon-based substrate, first layer made of nitride-based compound semiconductor containing first material, second layer made of nitride-based compound semiconductor containing second material having larger lattice constant than first material; channel layer on buffer layer and made of nitride-based compound semiconductor containing second material, buffer layer has: first composition graded layer between at least one of first layers and second layer immediately thereabove, made of nitride-based compound semiconductor whose composition ratio of second material is increased gradually upward, whose composition ratio of first material is decreased gradually upward; second composition graded layer between at least one of second layers and first layer immediately thereabove, made of nitride-based compound semiconductor whose first material is increased gradually upward, whose composition ratio of second material is decreased gradually upward, first composition graded layer is thicker than second composition graded layer.