Synthesis of mixed hexagonal-cubic BN thin films at low temperature

In this paper we present results connected to the production of mixed phase cubic- and hexagonal BN thin films with an RF magnetron sputtering machine, operating with RF-biased substrates at different self-bias voltages, at about room temperature, adopting a process atmosphere composed of argon and argon mixed with nitrogen. The films were deposited on silicon substrates and characterized by direct and Fourier transform infrared (IR, FTIR) spectroscopy, nanoindentation, Auger electron spectroscopy (AES), and scanning electron microscopy (SEM). Evidence of cubic phase formation, as given by IR spectroscopy, is found at self-bias voltage values up to -200 V.