Trench-gate semiconductor devices and their manufacture
US6541817B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Nov 29, 1999 |
| Grant date | Apr 1, 2003 |
| Priority date | — |
| Expiry date | Nov 29, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/516
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
In a trench-gate semiconductor device, for example a cellular power MOSFET, the gate (11) is present in a trench (20) that extends through the channel-accommodating region (15) of the device. An underlying body portion (16) that carries a high voltage in an off state of the device is present adjacent to a side wall of a lower part (20b) of the trench (20). Instead of being a single high-resistivity region, this body portion (16) comprises first regions (61) of a first conductivity type interposed with second regions (62) of the opposite second conductivity type. In the conducting state of the device, the first regions (61) provide parallel current paths through the thick body portion (16), from the conduction channel (12) in the channel-accommodating region (15). In an off-state of the device, the body portion (16) carries a depletion layer (50). The first region (61) of this body portion (16) is present between the second region (62) and the side wall (22) of the lower part (20b) of the trench (20) and has a doping concentration (Nd) of the first conductivity type that is higher than the doping concentration (Na) of the second conductivity type of the second region (62). A balance…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.