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. 10, 1984
Filed:
Nov. 15, 1982
Applicant:
Inventor:
Thomas P Giacomelli, Simi, CA (US);
Assignee:
TRE Semiconductor Equipment Corp., Woodland Hills, CA (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 53 ; 355 73 ; 355 76 ;
Abstract
A focusing apparatus for use in a step and repeat photo-exposure system is provided in which air jets are located immediately adjacent the exposure area of the exposure system. Back pressure of the air jets is sensed to determine the distance of the optical unit of the photo-exposure system to the surface of a semiconductor wafer being exposed. The average back-pressure is utilized to control movement of the optical system in order to achieve precise focusing. A map of the surface aberration of the wafer may be obtained by measuring the position of the camera at each die site after focusing has been achieved.