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. 01, 2015
Filed:
May. 27, 2014
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Shunichi Ito, Atsugi, JP;
Miyuki Hosoba, Isehara, JP;
Hideomi Suzawa, Atsugi, JP;
Shinya Sasagawa, Chigasaki, JP;
Taiga Muraoka, Atsugi, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
An object is to manufacture a semiconductor device including an oxide semiconductor at low cost with high productivity in such a manner that a photolithography process is simplified by reducing the number of light-exposure masks. In a method for manufacturing a semiconductor device including a channel-etched inverted-staggered thin film transistor, an oxide semiconductor film and a conductive film are etched using a mask layer formed with the use of a multi-tone mask which is a light-exposure mask through which light is transmitted so as to have a plurality of intensities. In etching steps, a first etching step is performed by dry etching in which an etching gas is used, and a second etching step is performed by wet etching in which an etchant is used.