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:
Apr. 15, 1997
Filed:
Nov. 14, 1995
Robert L Brown, Palo Alto, CA (US);
Hwan J Jeong, Los Altos, CA (US);
David A Markle, Saratoga, CA (US);
David S Pan, Fremont, CA (US);
Richard B Ward, Sunnyvale, CA (US);
Mark S Wanta, Sunnyvale, CA (US);
Ultratech Stepper, Inc., San Jose, CA (US);
Abstract
A substrate alignment and exposure system is disclosed The alignment is performed by capturing an image of the substrate with a pattern recognition system, determining the offset from the alignment and moving the substrate relative to the reticle to be in alignment. A first optical alignment system which captures an image of a position of the substrate off of the primary axis of the exposure optics is used to perform pre-alignment. A second optical alignment system captures an image of the reticle and the substrate through the lens of the exposure optics. The pattern recognition system recognizes the alignment keys on the reticle, alignment targets on the substrate, and computes their positions and displacement from alignment. The relative alignment can be direct or inferred. Any angular and translational misalignment is calculated. The pattern recognition system then moves the substrate to be in alignment with the reticle. In the present invention, any arbitrary feature on the reticle and substrate, including device features or specialized alignment keys and targets used by other exposure systems, can be recognized by the pattern recognition system and used for alignment.