Characterization of pulsed laser deposited boron nitride thin films on InP

A new technique for deposition of thin-film boron nitride (BN) from BN wafers has been demonstrated using a Q-switched ruby laser. The deposition rate was found to be∼7 A/pulse at an energy density of 2.5 J cm-2. X-ray photoelectron spectroscopy was used to confirm the film composition. Infrared absorption peaks were observed at 802, 1370, and 1614 cm-1 characteristic of B---N bonds. The films were found to have an indirect band gap of 4.1 eV with resistivity in excess of 1011 Ω cm and breakdown fields between 3.0x105---1.0x106 V cm-1. The dielectric constant of the films was in the range 3.19--3.28. The minimum interface state density on InP as obtained from C-V (1 MHz) analysis was typically 6.2x1010 cm-2 eV-1, which increased to 4.1x1011 cm-2 eV-1 after annealing at 200 degree C in argon. Scanning electron microscopy studies showed that this resulted in the development of micropores in the film