Deposition of BN thin films onto Si(1 0 0) substrate by PLD with nanosecond and femtosecond pulses in nitrogen gas background

BN thin films were deposited using pulsed laser deposition (PLD) by irradiating a hot-pressed h-BN target with a fourth harmonic wave of a Nd:YAG laser and a fundamental wave of a Ti:Sapphire laser in a background of nitrogen gas atmosphere without any aid of energetic techniques. Si(1 0 0) wafers with smooth and chemically etched surface were used as substrates. The films were characterized by SEM, XPS and FTIR. It was found that the cubic phase is present only in BN films deposited with UV nanosecond pulses. The absence of cubic phase in BN films deposited by femtosecond ablation is supposed to be due to high laser irradiance which causes the removal of unevaporated material from a soft target such as h-BN.