Effects of Gas Flow Variables on the Crystal Growth of Diamond in Hot Filament-Assisted CVD

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J. Korean Ceram. Soc. > Volume 31(1); 1994 > Article

Journal of the Korean Ceramic Society 1994;31(1): 88.

고온 필라멘트 다이아몬드 CVD에서 기체유동변수가 결정성장에 미치는 영향

서문규, 이지화¹

청주대학교 화학과
¹서울대학교 공업화학과

Effects of Gas Flow Variables on the Crystal Growth of Diamond in Hot Filament-Assisted CVD

ABSTRACT

Hot filament-assisted CVD was carried out to deposit diamond films on Si(100) substrate at 90$0^{circ}C$ using a 1% CH4-H2 mixture gas. Deposition was made at various conditions of mass flow rate of the feed gas (30~1000 sccm), pressure (2.5~300 Torr), and filament-substrate distance (4~15 mm), and the deposited films were characterized by SEM, XRD, and Raman spectroscopy. As the flow rate increases, the growth rate also increased but the crystallinity of the film was degraded. A longer filament-substrate distance simply caused both the growth rate and the crystallinity to become poorer. On the other hand, the pressure variation resulted in a maximum growth rate of 2.6 ${mu}{textrm}{m}$/hr at 10 Torr and the best film quality around 50 Torr, exhibiting an optimum condition. The observed trends were interpreted in terms of the flow velocity-dependent pyrolysis reaction efficiency and mass transport through the boundary layer.