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:
Oct. 30, 1979
Filed:
Apr. 17, 1978
Applicant:
Inventors:
Assignee:
Thomson-CSF, Paris, FR;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G03B / ; G03B / ;
U.S. Cl.
CPC ...
355 53 ; 355 77 ;
Abstract
The method consists in recording at least one reference mark on each of the patterns corresponding to the various levels of the circuit at a fixed point, in recording the reference mark of the first pattern in the semiconductor plate at the same time as the first pattern and then, after each positioning of the thin plate after the chemical treatments, in centering, by displacing the thin plate relative to the pattern, the images in the plane of the following pattern of at least two reference marks situated in the different zones with the complementary reference mark carried by the following pattern to be projected, the thin plate then being aligned with the following pattern to be projected.