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. 15, 2011
Filed:
Mar. 20, 2008
Mitsugu Tajima, Kawasaki, JP;
Mitsugu Tajima, Kawasaki, JP;
Fujitsu Semiconductor Limited, Yokohama, JP;
Abstract
A method of manufacturing a semiconductor device has forming a first silicon film over the first insulating film, forming a second silicon film over the first silicon film, a first etching the second silicon film in a depth, which the first silicon film is not exposed, in first condition, a second etching a remaining portion of the second silicon film and the first silicon film in a depth, which the first insulating film is not exposed, in second condition which gives a higher vertical etching component ratio than the first condition; and a third etching a remaining portion of the first silicon film in third condition which an etching rate for the first silicon film is larger than an etching rate for the first insulating film as compared to the second condition, wherein an impurity concentration of a first conductivity type of the first silicon film is higher than an impurity concentration of first conductivity type of the second silicon film.