Methods for improving well to well isolation
US6933203B2 · kind B2 · utility
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7References
25Claims
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Assignee
Inventors
Key dates
| Filing date | Nov 19, 2002 |
| Grant date | Aug 23, 2005 |
| Priority date | — |
| Expiry date | Nov 19, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D84/038
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Methods are provided for forming wells in a semiconductor wafer, in which p-wells and n-wells are formed in a substrate, and first p-type dopants are implanted into n-well regions while an n-well mask remains over the wafer to selectively decrease a substrate resistivity in the n-well regions beneath the n-wells. A subsequent blanket implantation provides second p-type dopants into isolation regions of the substrate beneath isolation structures, where the first and second p-type dopants improve well to well isolation without addition of extra masks to the fabrication process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.