Homoepitaxial growth of high quality (111)-oriented single crystalline diamond

Different deposition parameters for the growth of (111)-oriented single crystalline diamond samples were varied, such as temperature, methane concentration, methane/oxygen ratio and chamber pressure. It was shown that good quality (111)-oriented material can be deposited at low methane concentrations with oxygen addition at high temperatures (were high methane concentrations yield non-diamond phases in the grown crystal). Therefore, a growth temperature of 800 °C-850 °C is used along with a pressure of 200 mbar, a CH4/O2 ratio of 3 and a methane concentration of 0.3% (with the α, β and γ parameters seen in the image). Diamond layers with a thickness of 100 nm and 300 μm show RMS roughness values of around 0.26 nm and 200 nm, respectively.119