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:
Sep. 15, 1987
Filed:
Jul. 17, 1985
Katsuyoshi Washio, Hachioji, JP;
Makoto Hayashi, Hachioji, JP;
Tomoyuki Watanabe, Tokyo, JP;
Takahiro Okabe, Kodaira, JP;
Katuhiro Norisuye, Kodaira, JP;
Hitachi, Ltd., Tokyo, JP;
Hitachi Microcomputer Engineering, Ltd., Tokyo, JP;
Abstract
A semiconductor integrated circuit device incorporating bipolar transistors and IILs comprises respective buried layers in a substrate and active regions. A buried layer formed in the IIL region has a larger Gummel number than that of a buried layer formed in the bipolar transistor region so that a leakage current to the substrate is prevented. A larger Gummel number of the buried layer is accomplished by increasing the impurity concentration or the thickness of the layer. The device structure allows an enhanced circuit packing density, while suppressing a leakage current to the substrate.