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:
Jan. 23, 1990
Filed:
Oct. 06, 1988
Tadashi Kiriseko, Kanagawa, JP;
Fujitsu Limited, Kawasaki, JP;
Abstract
Automatic identification of each semiconductor wafer during wafer processing is achieved by the invention regardless of layers deposited on a code pattern. The code pattern, preferably, a bar code pattern, is formed on a front surface of the semiconductor wafer, and a light beam including infrared rays is irradiated onto a bottom surface thereof. The infrared rays easily penetrate through the silicon wafer and reflect from the bar code pattern formed on the front surface of the wafer. The reflected beam of infrared rays is received by a detector disposed on a back side of the wafer, and each wafer is identified by decoding the received signal. The bar code pattern can be directly formed by inscribing the wafer surface by a laser beam or inscribing a metal layer deposited thereon.