Highly oriented diamond films grown at high growth rate

Highly oriented diamond (HOD) films were grown at a high growth rate on (100) silicon substrates by microwave plasma chemical vapor deposition (MPCVD), following the standard bias-enhanced nucleation (BEN) process. The growth rate and diamond quality were investigated as a function of methane concentration in hydrogen (2-6%), and air/CH4 ratio (0 to 0.16). A four-fold increase in the growth rate of HOD films and a three times faster expansion and coalescence of (100) facets was observed within the above process window. The films with the best quality were grown under an air/CH4 ratio of 0.11 at methane concentration of 3.5%. The ratio of x-ray intensity between the first order twins and {1111} poles was only 1%. A detailed study of the crystalline quality and phase purity as a function of methane concentration and nitrogen addition is presented.