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:
Oct. 18, 2016
Filed:
Apr. 29, 2016
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Kei Kaneko, Kanagawa-ken, JP;
Mitsuhiro Kushibe, Tokyo, JP;
Hiroshi Katsuno, Ishikawa-ken, JP;
Shinji Yamada, Ishikawa-ken, JP;
Jumpei Tajima, Tokyo, JP;
Yasuo Ohba, Kanagawa-ken, JP;
Kabushiki Kaisha Toshiba, Minato-ku, JP;
Abstract
A nitride semiconductor wafer includes a silicon substrate, a first layer, a second layer, a third layer, a fourth layer, a fifth layer, and a sixth layer. The first layer is provided on the silicon substrate. The second layer is provided on the first layer. The third layer is provided on the second layer. The fourth layer is provided on the third layer. The fifth layer is provided on the fourth layer. The sixth layer is provided on the fifth layer. A composition ratio x4 of the fourth layer decreases in a first direction from the third layer toward the fifth layer. A maximum value of the composition ratio x4 is not more than a composition ratio of the third layer. A minimum value of the composition ratio x4 is not less than a composition ratio of the fifth layer.