Sputter synthesis of wafer-scale hexagonal boron nitride films via interface segregation

We demonstrated the crystal growth of wafer-scale hexagonal boron nitride (hBN) films on AlN template substrates by pulsed sputtering deposition using Fe catalysts. It was found that hBN films with high crystalline quality were formed at the hetero-interfaces between the Fe catalytic layers and the AlN templates. The full width at half maximum value of the E2g Raman spectrum for the hBN film was as small as 5.1 cm−1. The hBN film showed a highly c-axis-oriented structure and a strong near-band-edge deep ultraviolet emission at room temperature. The present results indicate that the sputter synthesis of hBN films via interface segregation opens a new pathway for the wafer-scale production of high-quality hBN films, and we envisage its potential applications in the fabrication of prospective hBN-based optoelectronic devices.