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:
Aug. 02, 1994
Filed:
Oct. 20, 1992
Juro Yasui, Osaka, JP;
Kiyoshi Araki, Osaka, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
An X-ray transmission film 2 of a SiN film is formed on the surface of a mask base 1. Formed on the surface of the X-ray transmission film 2 are an LSI pattern 3, and an alignment mark 4 composed of a convex portion 4a and a concave portion 4b. On the surface of the convex portion 4a is an alignment light reflection grating pattern 5 of a tungsten film. Formed on the surface of the concave portion 4b is a metal film 7 of a tungsten film. With this arrangement, a laser light beam 13 does not reach a semiconductor substrate 30 through the alignment mark 4. Thus, when detecting a first-order reflection diffracted light beam 14 from the alignment mark 4 by means of a photodetector, there is no inclusion of unwanted reflected light beams from the semiconductor substrate 30.