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:
Jun. 09, 1998
Filed:
Jun. 26, 1996
Masaaki Ikegami, Tokyo, JP;
Mitsubishi Denki Kabushiki Kaisha, Tokyo, JP;
Abstract
The bipolar semiconductor device fabricated according to the present invention have high CB junction breakdown voltage (BV.sub.CBO), small capacitance between collector and base and high response speed. A n.sup.+ type well diffused layer 105 to be a base for vertical type transistor is formed to reach to a p.sup.+ type buried region 104. Further, a p.sup.+ type diffused layer 106 is formed to reach to the p.sup.+ type buried region 104 and to surround the n.sup.+ type well diffused layer 105 at intervals of the distance (d). The product NA(104).times.ND(105) is adjusted to become larger then the product NA(106).times.ND(102) wherein NA(104) is an impurity concentration of said buried layer (104) of said first conductive type to be a collector; NA(106) is an impurity concentration of said diffusion region (106) to be a collector electrode; ND(102) is an impurity concentration of said epitaxial layer (102) of said second conductive type; ND(105) is an impurity concentration of said well region (105) of said second conductive type to be a base for transistor.