Bidirectional power FET with substrate-referenced shield
US4541001A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 23, 1982 |
| Grant date | Sep 10, 1985 |
| Priority date | — |
| Expiry date | Sep 23, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/117
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Bidirectional power FET structure is disclosed with high OFF state voltage blocking capability. A shielding electrode is insulated between first and second gate electrodes in a notch between laterally spaced source regions and channel regions joined by a common drift region around the bottom of the notch. The shielding electrode is ohmically connected to the substrate containing the common drift region to be at the same potential level thereof and within a single junction drop of a respective main electrode across the junction between the respective channel containing region and drift region. The steering diode function for referencing the shielding electrode is performed by junctions already present in the integrated structure, eliminating the need for discrete dedicated steering diodes. The shielding electrode prevents the electric field gradient toward the gate electrode on one side of the notch from inducing depletion in the drift region along the opposite side of the notch. This prevents unwanted inducement of conduction channels in the drift region during the OFF state of the FET.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.