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. 17, 1989
Filed:
Apr. 10, 1987
Takahide Ikeda, Tokorozawa, JP;
Atsuo Watanabe, Hitachiohta, JP;
Touji Mukai, Sanda, JP;
Masanori Odaka, Kodaira, JP;
Katsumi Ogiue, Hinode, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a semiconductor device of the type in which a bipolar element and MOS field-effect transistors are formed on one surface of a semiconductor substrate, this invention discloses a semiconductor device characterized in that first buried layers of a first conductivity type are formed within regions of the semiconductor substrate in which the bipolar element are formed, a second buried layer of the first conductivity and at least one MOS field-effect transistor type is formed within the semiconductor substrate facing at least the emitter of the bipolar element, and the depth from one surface of the semiconductor substrate to the second buried layer of the first conductivity type is less than the depth from that surface to the first buried layer of the first conductivity type. This invention can prevent any increase in the capacity of the MOS field-effect transistor, and can also improve the operating speed of the bipolar element.