Effects of Multiple Filament Geometry in the Hot Filament Deposition of Diamond Films
Abstract
Scaleup of hot filament chemical vapor deposition of diamond films requires knowledge of how filament geometry affects the deposition process. The effect of multiple filament geometry on the growth rate and surface morphology of diamond films is presented. Three factors were varied: the number of helical turns in a filament - 5, 10 or 15; the number of filaments present --1 or 2; and the CH4 fraction in the CH4-H2 feed gas mixture -- 0.25%, 0.5%, 0.75% or 1.0%. Other depositions parameters were 750 C substrate temperature, 52 standard cm/m total feed gas flow rate, and 5300 Pa deposition pressure. The deposition chamber volume was 1.9 liters. Increasing the CH4 concentration in the feed gas results in higher growth rates. However, increasing the number of filament turns in dual filament systems resulted in lower than expected growth rates for dual 10 and 15 turn filaments.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 12, 1991
- Accession Number
- ADA236708
Entities
People
- A. Feldman
- E. N. Farabaugh
- L. H. Robins
Organizations
- National Institute of Standards and Technology