Shallow trench isolation formation with spacer-assisted ion implantation
US6143624A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 14, 1998 |
| Grant date | Nov 7, 2000 |
| Priority date | — |
| Expiry date | Oct 14, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S438/981
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An insulated trench isolation structure is formed by ion implanting impurities proximate the trench edges to enhance the silicon oxidation rate and, hence, increase the thickness of the resulting oxide at the trench edges. Embodiments include masking and etching a barrier nitride layer, forming protective spacers on portions of the substrate corresponding to subsequently formed trench edges, etching the trench, removing the protective spacers, ion implanting impurities into those portions of the substrate previously covered by the protective spacers, and then growing an oxide liner. The resulting oxide formed on the trench edges is thick due to the enhanced silicon oxidation rate, thereby avoiding overlap of a subsequently deposited polysilicon layer and breakdown problems attendant upon a thinned gate oxide at the trench edges.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.