反向流动垂直喷淋式MOCVD反应器生长GaN的化学反应数值模拟

本文提出了MOCVD生长GaN的表面循环反应模型,将该反应模型应用于作者新近提出的反向流动垂直喷淋式反应器,进行三维数值模拟.得出反应器内流速、温度和TMGa浓度分布,以及GaN的生长速率分布.将此计算结果与传统的反应器情况进行对比,发现在相同参数情况下,两种反应器的衬底上方温度分布都比较均匀,近衬底处温度梯度较大,高温区域被压制在离衬底较近的区域,流线均比较平滑,在衬底上方没有明显的旋涡;新型反应器内反应气体在近衬底处的浓度均匀性以及GaN在基片表面的沉积均匀性都优于传统反应器,但沉积速率小于后者,大约只有后者的1/2.

Numerical Simulation on GaN Growth in Reverse-flow Showerhead MOCVD Reactors

The surface cycling reaction model on GaN growth in MOCVD process is presented.The reaction model is combined into 3D modeling of transport process in the newly designed reverse flow showerhead reactors.By numerical simulation,the growth velocity,temperature and concentration distributions are obtained and compared with those in traditional reactors.It is found that under the same operating conditions,the temperature and velocity fields are smooth in both reactors;no vortex flow exists above the susceptor.In the new reactor,the reactants' concentration distribution and GaN deposition uniformity are better than in the traditional reactor,but the deposition rate is smaller,which is about a half of the latter.