Fabrication method of a device isolation structure
US6258694A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 10, 1999 |
| Grant date | Jul 10, 2001 |
| Priority date | — |
| Expiry date | Sep 10, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76205
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A fabrication method of a device isolation structure. A patterned mask layer is formed on a silicon substrate. A dopant is doped into an exposed substrate to prevent a bird's beak silicon region from being oxidized in a first doping step. A spacer is formed on the sidewall of the mask layer. Portions of the silicon substrate are removed to form a trench by using the mask layer and the spacer as a mask. A second dopant is doped into the exposed silicon substrate on the bottom of the trench to benefit the oxidation of a desired field oxide region in a second doping step. A field oxide layer is formed to fill the trench in a field oxide process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.