Method for forming multiple doping level bipolar junctions transistors
US7449388B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2006 |
| Grant date | Nov 11, 2008 |
| Priority date | — |
| Expiry date | Oct 13, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/859
Abstract
A process for forming bipolar junction transistors having a plurality of different collector doping densities on a semiconductor substrate and an integrated circuit comprising bipolar junction transistors having a plurality of different collector doping densities. A first group of the transistors are formed during formation of a triple well for use in providing triple well isolation for complementary metal oxide semiconductor field effect transistors also formed on the semiconductor substrate. Additional bipolar junction transistors with different collector doping densities are formed during a second doping step after forming a gate stack for the field effect transistors. Implant doping through bipolar transistor emitter windows forms bipolar transistors having different doping densities than the previously formed bipolar transistors. According to one embodiment of the present invention, bipolar junction transistors having six different collector dopant densities (and thus six different breakdown characteristics) are formed.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.