N-well resistor as a ballast resistor for output MOSFET
US5712200A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 18, 1997 |
| Grant date | Jan 27, 1998 |
| Priority date | — |
| Expiry date | Feb 18, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D89/601
Abstract
A resistor formed in a well adjacent to a transistor serves as a ballast resistor for the transistor. The transistor is formed in a first region on a substrate. The first region is of a first conductivity type. A well of second conductivity type is formed adjacent to the first region. A gate region is formed over a portion of the first region. Concurrently, a covering is formed over a first area of the well. The covering and the gate region are comprised of the same material. Source/drain regions of the second conductivity type are formed on either side of the gate region. The source/drain regions are of the first conductivity type. A first source/drain region extends into the well. Concurrent to the forming of the source drain regions, a doped region is formed within the well. The doped region and the first source/drain region have the same doping density. The doped region is physically separated from the first source/drain region by the first area of the well. Contact regions for the transistor are formed within the second source/drain region and within the doped region.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.