BORON-NITRIDE COATING ON FUSED-SILICA AMPOULES FOR SEMICONDUCTOR CRYSTAL-GROWTH

Fused silica ampoules for use in Bridgman growth of semiconductor crystals were coated with boron nitride films by chemical vapor deposition from borazine. Ampoules coated for 20 h at 1100 degrees C yielded uniform, small grain hexagonal boron nitride films about 10 mu m thick. The coatings were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), contact angle measurements, and thickness measurements by profilometer. The coatings contained no hydrogen, appeared to possess a very uniform morphology, and showed high contact angles with molten CdTe. The low wetting nature of the coating makes it a promising container material for crystal growth.