Growth-modified thermal oxidation for thin oxides
US5132244A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jun 12, 1991 |
| Grant date | Jul 21, 1992 |
| Priority date | — |
| Expiry date | Jun 12, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/974
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
A method is disclosed for growing relatively thin (e.g., <250 .ANG.) thermal oxides which results in lowering the defect density, mobile ion concentration, interface trapped charge density, and stress of the structure. In particular, the prior art oxidation process is modified to include in situ preoxidation silicon surface treatments to improve the silicon nucleation surface. For example, gettering operations may be performed to remove metal-ion contaminants from the silicon nucleation surface, and high temperature annealing operations may be performed to remove any local stress gradients which exist in the silicon substrate during the initial stages of oxidation. By improving the silicon nucleation surface, the subsequently grown thin oxide will be improved in terms of the qualities mentioned above.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.