Method for reducing tungsten roughness and improving reflectivity
US8551885B2 · kind B2 · utility
65Cited by
77References
21Claims
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Key dates
| Filing date | Aug 29, 2008 |
| Grant date | Oct 8, 2013 |
| Priority date | — |
| Expiry date | Jun 11, 2029 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/76876
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
Methods of producing low resistivity tungsten bulk layers having lower roughness and higher reflectivity are provided. The smooth and highly reflective tungsten layers are easier to photopattern than conventional low resistivity tungsten films. The methods involve CVD deposition of tungsten in the presence of alternating nitrogen gas pulses, such that alternating portions of the film are deposited by CVD in the absence of nitrogen and in the presence of nitrogen. According to various embodiments, between 20-90% of the total film thickness is deposited by CVD in the presence of nitrogen.
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