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:
Jun. 03, 1986
Filed:
Jan. 23, 1985
Applicant:
Inventors:
Werner Tabarelli, Vaduz, LI;
Herbert E Mayer, Eschen, LI;
Assignee:
Perkin-Elmer Censor Anstalt, Vaduz, LI;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ;
U.S. Cl.
CPC ...
355 53 ; 355 43 ; 355 54 ;
Abstract
An apparatus for determining the focus state of a system for the projection exposure of a mask on a semiconductive substrate for producing integrated circuits without relatively displacing the mask, projection objective and substrate along the common optical axis, utilizes an arrangement for varying cyclically the optical path length for rays at least arising from a projected image on the substrate and running through the objective to a detector plane so that an intensity measurement of the light intensity at this plane indicates the path length required for sharpness and hence the focus state of the projection assembly.