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:
Feb. 16, 1993
Filed:
Aug. 22, 1990
Masashi Ohmori, Itami, JP;
Youichi Midou, Itami, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
In a method of manufacturing semiconductor devices by using a semiconductor wafer having a circuit area in which a circuit pattern is to be formed and a character printing area in which a lot number pattern for recording characters used for product management is to be formed, etching the surface of the semiconductor wafer to form the lot number pattern in the character printing area, forming a metallic layer over the surface of the semiconductor wafer, and selectively removing the portion of the metallic layer located on the circuit area but not used as the circuit pattern and the portion of the metallic layer located on the character printing area simultaneously.