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. 17, 2004
Filed:
Jan. 27, 2000
Komatsu Electronic Metals Co., Ltd., Tokyo, JP;
Abstract
To provide a semiconductor wafer having dot marks produced by irradiating laser beam capable of selecting a marking region capable of reading and writing marks in a state in which the marks hardly vanish and the semiconductor wafer is contained in a wafer cassette, inscribing information of an identification number or electric properties in the region and grasping past history by a unit of the wafer in processing steps or semiconductor fabrication steps thereafter, a very small dot mark is formed by irradiating laser having a diameter of 1 through 13 &mgr;m on an inner wall face of a notch ( ) formed on an outer peripheral face of a semiconductor wafer (W), particularly on an inclined face of its peripheral edge.