Shallow trench isolation fill by liquid phase deposition of SiO2
US7273794B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 11, 2003 |
| Grant date | Sep 25, 2007 |
| Priority date | — |
| Expiry date | Sep 24, 2024 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH10D86/01
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
To isolate two active regions formed on a silicon-on-insulator (SOI) substrate, a shallow trench isolation region is filled with liquid phase deposited silicon dioxide (LPD-SiO2) while avoiding covering the active areas with the oxide. By selectively depositing the oxide in this manner, the polishing needed to planarize the wafer is significantly reduced as compared to a chemical-vapor deposited oxide layer that covers the entire wafer surface. Additionally, the LPD-SiO2 does not include the growth seams that CVD silicon dioxide does. Accordingly, the etch rate of the LPD-SiO2 is uniform across its entire expanse thereby preventing cavities and other etching irregularities present in prior art shallow trench isolation regions in which the etch rate of growth seams exceeds that of the other oxide areas.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.