NMOS source/drain doping with both P and As
US4851360A · kind A · utility
16Cited by
3References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Mar 9, 1988 |
| Grant date | Jul 25, 1989 |
| Priority date | — |
| Expiry date | Mar 9, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S257/917
Abstract
A process for forming N-channel MOS sources and drains, by implanting both phosphorus and arsenic. The high diffusivity of phosphorus causes it to diffuse in advance of the bulk of the arsenic, so that, after annealling, the source/drain regions have graded regions of gradually decreasing conductivity adjacent to the end of the channels. Thus the electric potential gradient at the ends of the channels is reduced, and impact ionization and hot carrier effects are avoided. The effective radius of the source (or drain) junction is increased, providing increased breakdown voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.