Reduced mask count process for manufacture of mosgated device
US6893923B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 7, 2002 |
| Grant date | May 17, 2005 |
| Priority date | — |
| Expiry date | Mar 14, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D64/519
Abstract
A process for forming a power MOSFET enables the connection a metal gate electrode to the conductive polysilicon gates in the active area without an additional mask step. In the process, a groove is formed in the field oxide during the active area mask step. Conductive polysilicon is then formed over the active area and into the groove. At least one window is formed over the groove along with the mask window for forming the channel and source implant windows, and the polysilicon is etched to the silicon surface in the active area, but a strip is left in the groove. This strip is contacted by gate metal during metal deposition. Thus, gate metal is connected to the polysilicon without an added mask step.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.