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:
Dec. 03, 2013
Filed:
Feb. 14, 2011
Shinya Sasagawa, Chigasaki, JP;
Masashi Tsubuku, Atsugi, JP;
Hitoshi Nakayama, Atsugi, JP;
Daigo Shimada, Atsugi, JP;
Shinya Sasagawa, Chigasaki, JP;
Masashi Tsubuku, Atsugi, JP;
Hitoshi Nakayama, Atsugi, JP;
Daigo Shimada, Atsugi, JP;
Semiconductor Energy Laboratory Co., Ltd., Atsugi-shi, Kanagawa-ken, JP;
Abstract
A transistor is manufactured by a method including: forming a first wiring layer; forming a first insulating film to cover the first wiring layer; forming a semiconductor layer over the first insulating film; forming a conductive film over the semiconductor layer; and performing at least two steps of etching on the conductive film to form second wiring layers which are apart from each other, wherein the two steps of etching include at least a first etching process performed under the condition that the etching rate for the conductive film is higher than the etching rate for the semiconductor layer, and a second etching process performed under the condition that the etching rates for the conductive film and the semiconductor layer are higher than those of the first etching process.