Ultra dense trench-gated power-device with the reduced drain-source feedback capacitance and Miller charge
US6683346B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Mar 7, 2002 |
| Grant date | Jan 27, 2004 |
| Priority date | — |
| Expiry date | May 24, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/513
Abstract
The cellular structure of the power device includes a substrate that has a highly doped drain region. Over the substrate there is a more lightly doped epitaxial layer of the same doping. Above the epitaxial layer is a well region formed of an opposite type doping. Covering the wells is an upper source layer of the first conductivity type that is heavily doped. The trench structure includes a sidewall oxide or other suitable insulating material that covers the sidewalls of the trench. The bottom of the trench is filled with a doped polysilicon shield. An interlevel dielectric such as silicon nitride covers the shield. The gate region is formed by another layer of doped polysilicon. A second interlevel dielectric, typically borophosphosilicate glass (BPSG) covers the gate. In operation, current flows vertically between the source and the drain through a channel in the well when a suitable voltage is applied to the gate.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.