Crystallinity improvement of hexagonal boron nitride films by molybdenum catalysts during microwave plasma chemical vapor deposition and post-annealing

Hexagonal boron nitride (hBN) is a promising deep ultraviolet light emitter. Here we report the catalytic growth of hBN films by microwave plasma chemical vapor deposition (MPCVD). The hBN films were first grown on Mo/Si substrate from a gas mixture of N2, BF3, and H2 and then annealed in nitrogen for 3 h at 900 °C. The Mo catalysts exhibit obvious catalyzing effects in improving the crystallinity of the hBN films during the growth and annealing processes. Well-crystallized hBN films with small Raman peak width of 9.3 cm−1 and sharp photoluminescence emission peak at 293 nm were obtained.