Effect of process parameters on synthesis of aluminum nitride powder prepared by chemical vapor deposition

Ultrafine aluminum nitride (AlN) powders were obtained by the chemical vapo r deposition (CVD) process via the AlCl3-N-2-NH3 system operated at various temperatures and different mixing modes of AlCl3 and NH3 gases. X-ray diff raction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscope (TEM) and electron diffraction (ED) were utilized to s tudy the effect of process parameters on the synthesis and characterization of the AlN powders. It had been shown that all of the obtained powders wer e exclusively identified to be the single phase AlN and were indifferent to the different mixing modes AlCl3 and NH3 gases. The yield of synthesized A lN powder was affected by the entries mixing position of the reacting gases of AlCl3 and NH3. The yield increased from 13% to 82% where the mixed posi tion was shifted from the front edge to middle point of the quartz tube. On the other hand, the yield increased from 5% to 82% as the reaction tempera ture increased from 600 degreesC to 1050 degreesC. The morphology of the Al N powders was affected by the diameter of a feeding nozzle and mixing mode of AlCl3 and NH3 gases. (C) 2001 Kluwer Academic Publishers.