Birdsbeak encroachment using combination of wet and dry etch for isolation nitride
US6066545A · kind A · utility
132Cited by
2References
4Claims
0Family size
Assignee
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Key dates
| Filing date | Dec 7, 1998 |
| Grant date | May 23, 2000 |
| Priority date | — |
| Expiry date | Dec 7, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76202
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A technique for reducing active area encroachment (birdsbeak) by using a polysilicon hard mask combined with both wet and dry etch for the isolation nitride. This process forms a thinner layer of nitride adjacent the openings for oxide growth, which reduces stress at the silicon/nitride interface. The advantages include control over birdsbeak, reliable gate oxide quality, low junction leakage current, an improved active area, improved isolation, low peripheral junction leakage, and higher field transistor threshold voltage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.