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:
Jul. 12, 1994
Filed:
Dec. 21, 1992
David A Markle, Saratoga, CA (US);
Gerald J Alonzo, Los Altos, CA (US);
Hwan J Jeong, Los Altos, CA (US);
Ultratech Stepper, Inc., , US;
Abstract
Disclosed is tilt-sensing means that employs a point source of alternate 1st or 2nd divergent light beams which, after passing through collimating lenses of the Half-Field Dyson projection optics of the stepper, are separately incident on and reflected from a reflective pattern disposed on the surface of a reticle and from a reflective surface of a wafer, together with two-dimensional position detection means responsive to the position of each of the reflected alternate 1st or 2nd divergent light beams, for independently sensing the angular position of the surface of the reticle and the angular position of the surface of the wafer to determine thereby whether or not the surface of the reticle and the surface of the wafer are substantially parallel to one another. This permits adjustment means of the stepper, which is responsive to the respective surfaces having been determined by the tilt-sensing means to be not parallel to one another, to angularly adjust the angular position of at least one of the reticle and the wafer to bring the respective surfaces thereof into a substantially parallel relationship with one another.