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:
Jan. 26, 1993
Filed:
Apr. 19, 1991
Hiromasa Shibata, Tokyo, JP;
Sortec Corporation, Tokyo, JP;
Abstract
The present invention relates to position detection, and aligning structure utilizing optical heterodyne method in semiconductor ultra fine processing or ultra accurate measuring. This is to provide a structure which contains pitches of not less than two kinds with respect to grating pitches of diffraction gratings which directly give influences to signal detecting range and detecting resolution, or which contains different values of not less than two kinds with respect to absolute values n of an order of .+-.n-th order injecting directions (or .+-.n-th order diffraction directions) to be determined by said grating pitches, so as to enable to enlarge a detecting range as maintaining a required detecting resolution (or a structure which can take out diffracted lights in different diffraction directions of not less than two).