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:
Aug. 01, 1995
Filed:
Jul. 12, 1993
Blandine Minghetti, Vaulnaveys le Haut, FR;
Annie Tissier, Saint Ismier, FR;
Alain Prola, Grenoble, FR;
Eric Schwartz, Seyssins, FR;
France Telecom, Paris, FR;
Abstract
A process and device for adjusting a photolithographic exposure machine, which is used for manufacturing integrated circuits. A guide wafer being furnished with identical test patterns, these test patterns are successively illuminated with white light beam and the coefficient of reflectivity of each test pattern is thus measured. For each location of the corresponding pattern, the law of correspondence of the coefficient of reflectivity as a function of the defocusing parameter for the illuminating beam is thus established. The optimum sharp focus value is determined by criterion of threshold of the value of the coefficient of reflectivity.