针对行星式MOCVD(Metal Organic Chemical Vapor Deposition)反应器进口结构对AlN生长的化学反应路径和生长速率的影响进行数值模拟研究,通过改变反应器进口形式、数量以及隔板位置发现,二重进口反应器倒置进口(即Ⅲ族在下,Ⅴ族在上)时,衬底前端的含Al粒子浓度明显升高,尤其是MMAl的浓度比传统进口反应器高两个数量级,气相反应中热解路径占主导,薄膜生长速率明显提高。在倒置进口的基础上优化隔板位置,生长速率略微降低,但薄膜均匀性明显改善。当反应器进口数量从二重变为三重和五重,反应从热解路径占主导变为热解路径和加合路径共同作用,薄膜生长速率逐渐增加,而均匀性明显改善。

The influence of the inlet structure of planetary reactor on gas reaction path and growth rate in AlN-MOCVD was studied by numerical simulation. By varying the reactor inlet mode, inlet number and position of inlet separator, it is found that, for the inverted two-inlet reactor, i.e., group-III below and group-V above, the concentration of Al-containing particles are higher near the front edge of the substrate, especially the concentration of MMAl is about two orders of magnitude than that of the conventional reactor. Thus the reaction is dominated by the pyrolysis path, and the film growth rate is higher. By optimizing the position of the inlet separator for the inverted inlet, better film uniformity is obtained and the growth rate slightly reduced. When the number of reactor inlets increase from two-inlet to three-inlet and five-inlet, the reaction path changes from the pyrolysis-dominated to the pyrolysis and adduct joined action path, the growth rate increases gradually and film uniformity increases significantly.