System to improve ser immunity and punchthrough
US6455363B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 3, 2000 |
| Grant date | Sep 24, 2002 |
| Priority date | — |
| Expiry date | Jul 3, 2020 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/854
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method for fabricating an SRAM device having a standard well tub, where an additional well tub is deposited within the standard well tub. In this manner, the dopant concentration is increased in the well area of the SRAM device, which increases both the isolation punchthrough tolerance and the SER immunity of the device. The additional well tub is deposited to a depth that is shallower than the standard well tub. The additional well tub is deposited using an ion implantation process using the same mask set as that used for the threshold voltage adjustment deposition. Thus, no additional mask layer is required to deposit the additional well tub, and the all of the expenses normally associated with an additional mask layer are avoided.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.