Thermal Plasma Diamond Deposition: Film Quality and Morphology Under High-Growth Rate Conditions

点击翻译按钮获取中文摘要

Abstract Girshick CTS-9424271 The PI points out that a crucial issue in the commercialization of CVD diamond lies in the development of morphology control under high growth rate conditions. This proposal addresses this key issue by considering the following objectives: (1) To relate diamond growth rates and the morphology parameter a to process conditions in an rf thermal plasma reactor; (2) To relate a to actual surface conditions during film growth, i.e. , species concentrations and surface temperature; (3) To relate film quality to surface conditions, growth rates and morphology; (4) To assess the feasibility of growing smooth 100-textured films at high growth rates. The PI plans to attain these research objectives through a combination of diamond growth experiments involving on-line diagnostics for temperature and species concentrations, and off-line diagnostics to analyze the deposited films and by carrying out numerical modeling. The experiments will make use of a reactor in which an rf plasma is accelerated through a nozzle to produce thin boundary layers, which are known to promote high growth rates. The experimental parameters to be varied include the flow rates of hydrogen, methane and argon, the substrate surface temperature, the nozzle exit diameter, and chamber pressure. Diagnostics will include gas chromatography and mass spectroscopy of gaseous samples obtained through micro-orifices located in the substrate, and non-intrusive techniques of emission spectroscopy and laser induced fluorescence. A previously existing code which treats the rf plasma, the chemical kinetics in the substrate boundary layer, and the film growth chemistry at the diamond surface will be modified to account for the new reactor design.