Diamond deposition at low substrate temperatures

Abstract

Three different experimental approaches are reported for the deposition of diamond at low substrate temperatures. These are a remote thermal CVD technique, and two different means for achieving remote microwave plasma enhanced CVD. Using these approaches it has been shown that diamond can he deposited at low temperatures and on potentially reactive substrates such as fused silica. In addition it is clearly shown that the presence of the substrate within a plasma discharge or immediately adjacent to a hot refractory metal surface is not a prerequisite for the crystallization of diamond from hydrocarbon-hydrogen mixtures. Well crystallized as well as nanocrystalline diamond coatings were obtained at substrate temperatures as low as 430 to 450 °C which offers significant promise for future developments. Growth rates varied with the method used, from 200 to 300 A/h for well crystallized diamond to 0.5 to 1.0 ltm/h for nanocrystalline coatings.