AlCl_3-NH_3-N_2体系化学气相淀积AIN超细粒子 Ⅱ.AIN的粒度及分布模型

Synthesis of AlN Ultrafine Particles by CVD of AlCl_3-NH_3-N_2 System Ⅱ. Modelling Study of Particle Size and Distribution of AlN

考虑轴向温度分布和浓度分布,建立了热化学气相淀积反应器中描述粒子粒度及分布的一维反应-凝并模型。研究了AlCl_3-NH_3-N_2体系物系参数和操作参数对AlN超细粒子粒度及分布的影响。温度通过改变反应速率、气体粘度和平均分子自由程等影响AlN粒子的合成,并存在最佳温度分布;随停留时间的增加,AlN粒子粒度增大,几何标准方差GSD减小;反应物浓度升高时,AlN粒子粒度增大,但GSD变化不大。模型化研究结果和实验结果相一致。

Considering the axial temperature and concentration profiles in the thermal chemical vapor deposition (CVD) reactor, a one-dimensional reaction-coagulation model of particle size and distribution was established. For the AlCl_3-NH_3-N_2 system, the effects of the material and operation parameters on AlN particle size and distribution were studied. It was found that temperature affected AlN particle properties by changing reaction rate, viscosity and mean free path of g(?)ses. The particle size increased with increasing residence time and reactant concentration. The AlN particle size distribution got narrower with increasing residence time, but changed little with increasing reactant concentration. The calculated results from model were consistant with that of experiment.