氮化物MOCVD反应室流场的仿真与分析

Simulation and Analysis of Flow Field in Nitride MOCVD Reactor Chamber

在立式MOCVD反应室中,通过对生长氮化镓(GaN)薄膜材料的仿真,发现衬底表面反应物三甲基镓物质的量的浓度分布与实际生长的GaN薄膜的厚度分布一致,同时,仿真结果表明,薄膜的厚度分布与反应室内涡旋的分布相关。通过分析涡旋产生的原因,对反应条件和反应室的几何条件作了进一步优化,发现在较低的反应室压强、较低的壁面温度和较大的气体入口半径条件下,能使涡旋明显减小,提高薄膜生长的均匀性。

Simulation of the GaN growth in the vertical MOCVD reactor chamber was performed.It was observed that the molar concentration distribution on the surface of the substrate obtained from simulation of the trimethylgallium （TMG）,is in good agreement with the thickness distribution of the GaN film.And the results of the simulation showed that the thickness distribution of the film is concerned with that of the vortex flow in the reactor chamber.By analysis of the reason of the vortex flow,the reaction conditions and the geometry shape of the reactor chamber had been optimized.It was found that the vortex flow is reduced significantly,under the conditions of lower pressure,lower wall temperature and bigger radius of gas inlet of the reactor chamber,and the uniformity of the film growth is also improved.