摘要
根据MOCVD过程薄膜生长的基本要求,总结出各种MOCVD反应器普遍适用的最佳输运过程的5个条件,即均匀浓度边界层、均匀速度边界层、均匀温度边界层、分隔进口但反应前混合均匀、以及迅速排出尾气不再发生混合.对照最佳输运过程条件,分别对水平式、行星式、垂直喷淋式、高速转盘式反应器进行了分析和讨论.水平式反应器的主要问题是反应物的沿程损耗、热对流涡旋以及侧壁效应,造成基片沿横向和纵向的厚度和浓度不均,因此只适合实验室应用.垂直式反应器通过高速旋转或近距离喷射,可以均匀分配反应物浓度,并抑制热对流涡旋.其主要困难是反应后的尾气不能及时排出,从而仍存在径向浓度不均,造成基片沿径向的厚度和浓度的波动.商用的垂直式反应器还面临托盘直径进一步扩大的难度.文章为MOCVD反应器的控制和设计提供了重要的参考依据.
Based on the growth requirement in MOCVD processes,the five optimum transport conditions are summarized as：uniform concentration boundary layer,uniform velocity boundary layer,uniform temperature boundary layer, reactants mixed uniformly before entering the reaction zone,and the exhaust gas expelled＇quickly without remixing with the reactants. Compared with the optimum conditions, the current MOCVD reactors of horizontal, vertical, planetary,showerhead, and RDR types are discussed. The main problems in horizontal reactors are reactant depletion, thermal convection, and reactor side effects. Using injection from showerheads and high speed susceptor rotation, the vertical reactors can obtain much more uniform boundary layers. The main problems in vertical reactors are the difficulty in expelling the exhaust gas without remixing with reactants and the difficulty in further enlarging the diameter of the rotating susceptor.
基金
国家自然科学基金资助项目(批准号:60376006)~~
