Complementary bipolar transistor structure and method for manufacture
US4997776A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 20, 1990 |
| Grant date | Mar 5, 1991 |
| Priority date | — |
| Expiry date | Jun 20, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S148/06
Abstract
A complementary bipolar transistor structure having one symmetrical intrinsic region for both the NPN and PNP transistors and a method for fabricating the structure. The transistor structure includes a vertical NPN transistor operating in the upward direction and a vertical PNP transistor operating in a downward direction. In the method, the sub-emitter and the sub-collector regions are formed by depositing a first epitaxial layer of semiconductor material of a first conductivity type on the surface of a semiconductor substrate of a second conductivity type, and forming the sub-collector by etchig a shallow trench in the first layer and depositing semiconductor material of a second conductivity tyep by LTE and planarizing. The intrinsic regions for both of the transistors are formed by depositing a second layer of semiconductor material of the second conductivity type on the surface of the first layer and a third layer of semiconductor material of the first conductivity type on the surface of the second layer by either LTE or MBE. In one embodiment, the second and third layers are provided with a uniform vertical doping profile for one thickness of the layer and a graded doping pro…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.