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. 12, 2004
Filed:
Apr. 15, 2003
Yasuhiko Kouno, Naka, JP;
Hideo Miura, Sendai, JP;
Nobuyoshi Matsuura, Takasaki, JP;
Masaharu Kubo, Hachioji, JP;
Renesas Technology Corporation, Tokyo, JP;
Abstract
Gate oxide films, gate electrodes, base regions and emitter regions, which constitute IGBTs, are formed on a semiconductor wafer. A silicon oxide film is formed on the gate electrodes. Further, an emitter electrode is formed thereabove, and a passivation film is formed over the emitter electrode. Thereafter, an internal area of a back surface of the semiconductor wafer is polished to form a protrusion at its outer peripheral portion. Afterwards, an impurity is injected from the back surface of the semiconductor wafer to form a collector region. After a collector electrode is further formed, the semiconductor wafer is mounted on a stage smaller than the internal area and subjected to dicing along scribe areas. Thus, the strength of the semiconductor wafer is held by the protrusion, and cracking or the like of the semiconductor wafer can be reduced owing to the execution of the dicing in the above-described manner.