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 vapor deposition (CVD) process via the AlCl3-N2-NH3 system operated at various temperatures and different mixing modes of AlCl3 and NH3 gases. X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscope (TEM) and electron diffraction (ED) were utilized to study the effect of process parameters on the synthesis and characterization of the AlN powders. It had been shown that all of the obtained powders were exclusively identified to be the single phase AlN and were indifferent to the different mixing modes AlCl3 and NH3 gases. The yield of synthesized AlN 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 position 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 temperature increased from 600°C to 1050°C. The morphology of the AlN powders was affected by the diameter of a feeding nozzle and mixing mode of AlCl3 and NH3 gases.