PECVD and CVD processes for WNx deposition
US6635570B1 · kind B1 · utility
Inventors
Key dates
| Filing date | Sep 30, 1999 |
| Grant date | Oct 21, 2003 |
| Priority date | — |
| Expiry date | Sep 30, 2019 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/32051
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Improvements to chemical vapor deposition processes are taught for depositing tungsten nitride in semiconductor manufacturing processes. In one irmproved process NF3 is used as a source of nitrogen, and a plasma is introduced under controlled conditions to control particle formation and lower the temperature at which acceptable films may be produced. In another set of processes substantially pure tungsten is produced by rapid thermal annealing of substantially amorphous tungsten nitride at temperatures lower than achieved in the art, by using hydrogen in the ambient atmosphere. In yet another set of new processes particle formation and step coverage enhancement when using NH3 as a nitrogen source is controlled by limiting the pressure at which source gases mix, by unique wall coating technique, and by controlling chamber wall temperature. In still another set of unique processes a graded film on oxide, starting with tungsten silicide quickly grading to tungsten nitride is produced by introducing silane in the NH3 chemistry under controlled conditions.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.