Stabilization in device characteristics of a bipolar transistor that is included in a semiconductor device with a CMOSFET
US6803634B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 2002 |
| Grant date | Oct 12, 2004 |
| Priority date | — |
| Expiry date | Nov 7, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/401
Abstract
In the manufacturing process of a Bi-CMOS semiconductor device, which includes a CMOSFET and a bipolar transistor, the steps for forming a well region, source regions, and drain regions of the CMOSFET are also used for forming the bipolar transistor. One of the steps is used for introducing impurities of the same conductivity type in a surface of a base region of the bipolar transistor in order to form a high impurity concentration region in the surface. The high impurity concentration region is formed such that the distance between an emitter region of the bipolar transistor and the high impurity concentration region becomes 1 to 2 &mgr;m. The shift in device characteristics of the bipolar transistor is improved by the high impurity concentration region even if the impurity concentration is relatively low at the surface of the base region of the bipolar transistor.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.