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. 25, 2001
Filed:
Jan. 10, 2000
Tsutomu Miyatake, Kiyose, JP;
Sumitomo Heavy Industries, Ltd., Tokyo, JP;
Abstract
The exposure surface of a wafer to be exposed is formed with a wafer mark having edges for scattering incident light. The edge of the wafer mark has a curved portion whose image vertically projected upon a plane in parallel to the exposure surface has a curved shape. The surface of an exposure mask is formed with a mask mark having edges for scattering incident light. The edge of the exposure mask has a curved portion whose image vertically projected upon a plane in parallel to the surface of the exposure mask has a curved shape. The wafer and exposure mask are juxtaposed with and spaced apart by a gap from the exposure surface of the wafer. Illumination light is applied to the curved portions of the edges of the wafer and mask marks. Light scattered from the wafer and mask marks is observed along a direction oblique to the exposure surface to thereby detect a relative position of the wafer and exposure mask.