Characterization of boron nitride film synthesized by helicon wave plasma-assisted chemical vapor deposition

Abstract

The microstructure of boron nitride film grown on Si (100) at various temperatures by a helicon wave plasma chemical vapor deposition using borazine as a precursor was investigated. The optimum substrate bias voltage for c-BN growth by the employed deposition process ranged from -200 to -400 V. HRTEM images revealed that the film included an interlayer of a-BN and h-BN followed by c-BN layer. A sufficient accumulation of compressive stress is required before c-BN growth. With increasing interlayer thickness and random orientation at high growth temperatures, residual compressive stress seems to decrease owing to an annealing effect. At the initial c-BN growth stage, the congruent growth of hexagonal and cubic phases occurs at low temperatures of 300 and 500 degrees C; however, c-BN growth proceeds only after the formation of h-BN layer at the high temperature of 800 degrees C. The hydrogen content in the BN films synthesized at lower temperatures was degrees 8%, while that of the BN film synthesized at 800 degrees C was similar to 2.6%. In addition, with increasing the temperature, the decreasing tendency in c-BN IR mode FWHM indicates enhancement of c-BN crystallinity. (C) 2000 Elsevier Science S.A. All rights reserved.