Diamond growth by hollow cathode arc plasma chemical vapor deposition

摘要

Hollow cathode are plasma chemical vapor deposition was employed to grow crystalline diamond films using 1.5 to 7 of methane in hydrogen. The growth rate was as high as 3.2 mu/h when using 5 CH4/H-2 at a pressure of 15 Torr and a substrate temperature of 1083 K. However, an intermediate layer of several hundred nanometers was observed at the him-substrate interface by cross-section SEM. Raman and XPS characterizations showed that the interfacial layer consisted of sp(2) carbon and TaC with Ta vaporized from the hot cathode tube. XRD and XPS results further showed that the deposited diamond films also contained TaC. Ta composition in the film increased with the increase of growth pressure, the reduction of substrate temperature, and the increase of H-2 how in the Ta tube. The diamond films deposited by using CHCl3 as carbon source had Ta concentrations one order of magnitude higher than those using CH4, as shown by XPS results, but the nucleation densities using CHCl3 were always higher than those using CH4. References: 27