High DC breakdown voltage field effect transistor and integrated circuit
US5162888A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 12, 1989 |
| Grant date | Nov 10, 1992 |
| Priority date | — |
| Expiry date | May 12, 2009 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D30/603
Abstract
A field effect transistor device formed on an integrated circuit chip substrate and driven by the on-chip voltages having a well region formed in the substrate, and source and drain regions one of which is formed in the well region. The well region has a lower doping concentration than the source and drain regions and is of the same conductivity type. The well region provides a reduced electric field gradient at the source/substrate or drain/substrate junction and significantly increases the breakdown resistance of the device to DC voltages higher than the on-chip voltages. An input/output protection circuit employing the field effect transistor coupled in series between an integrated circuit output pad and the active devices on the chip providing ability to withstand coupling of the pad to a relatively high DC voltages.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.