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:
Sep. 23, 2025
Filed:
Nov. 22, 2022
Sumitomo Chemical Company, Limited, Tokyo, JP;
Ryota Isono, Hitachi, JP;
Takeshi Tanaka, Hitachi, JP;
SUMITOMO CHEMICAL COMPANY, LIMITED, Tokyo, JP;
Abstract
There is provided a Group III nitride stack in which the concentration of an impurity in the buffer/channel layer of an HEMT is suppressed to a predetermined range. The Group III nitride stack includes a first layer comprising gallium nitride, and a second layer on the first layer, the second layer comprising a Group III nitride having a lower electron affinity than gallium nitride. The first layer includes a lower layer and an upper layer on the lower layer. The carbon concentration in the upper layer is lower than a carbon concentration in the lower layer, the hydrogen concentration in the upper layer is lower than a hydrogen concentration in the lower layer, the carbon concentration in the upper layer is 5×10cmor less, and the hydrogen concentration in the upper layer is 1×10cmor less.