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. 28, 2017
Filed:
Jul. 30, 2015
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Shunpei Yamazaki, Setagaya, JP;
Masashi Tsubuku, Atsugi, JP;
Ryosuke Watanabe, Yamato, JP;
Masashi Oota, Atsugi, JP;
Noritaka Ishihara, Kawasaki, JP;
Koki Inoue, Atsugi, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
An oxide semiconductor stacked film which does not easily cause a variation in electrical characteristics of a transistor and has high stability is provided. Further, a transistor which includes the oxide semiconductor stacked film in its channel formation region and has stable electrical characteristics is provided. An oxide semiconductor stacked film includes a first oxide semiconductor layer, a second oxide semiconductor layer, and a third oxide semiconductor layer which are sequentially stacked and each of which contains indium, gallium, and zinc. The content percentage of indium in the second oxide semiconductor layer is higher than that in the first oxide semiconductor layer and the third oxide semiconductor layer, and the absorption coefficient of the oxide semiconductor stacked film, which is measured by the CPM, is lower than or equal to 3×10/cm in an energy range of 1.5 eV to 2.3 eV.