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:
Apr. 18, 2000
Filed:
Feb. 27, 1998
Sanyo Electric Co., Ltd., Osaka, JP;
Abstract
A lead electrode (57) is formed to expose an active base region (61). On the lead electrode (57) is formed a lead electrode (64) for an emitter electrode via an insulation film (56). When a base contact hole (65') for exposing the lead electrode (57) and an emitter contact hole for exposing the lead electrode (64) are formed at the same time, total thickness of the insulation film on the lead electrode (64) is thinner than that of the insulation layer on the lead electrode (57), which results in excessive etching on a part of the surface of the lead electrode to form recess. The lead electrode (64) is led out to a LOCOS film to form the emitter contact hole in a region on the LOCOS film to expose the lead electrode (64). Therefore, the recess having been formed on the lead electrode (64) upon forming the emitter contact hole is made to form on the LOCOS film outside the emitter region. The recess prevents depth of the emitter region from dispersing.