UV-IRRADIATION AND THERMAL-ANNEALING STUDIES IN AMORPHOUS HYDROGENATED BORON-NITRIDE THIN-FILMS

Both photoproduction and photobleaching of dangling bonds by uv irradi ation and thermal annealing were observed by electron spin resonance ( ESR) in amorphous hydrogenated boron nitride. A model involving long-r ange hydrogen diffusion and hydrogen evolution is proposed to account for the ESR spectral line shapes observed after UV irradiation and the rmal annealing. A Gaussian distribution of activation energies for the long-range hydrogen diffusion was used to explain the observed decrea se in spin susceptibility after thermal annealing. A best fit to the s pin susceptibility data gave an average activation energy of 0.0475 eV and a half-width of this Gaussian distribution of 0.027 eV.