氮化鎵半導體材料因為有相當高的能隙與電子遷移率而逐漸在各種半導體應用逐漸受到重視，其中包括紫外發光元件、高功率元件以及高頻率通訊元件，而金屬有機化學氣相沉積(Metal organic chemical vapor deposition, MOCVD)為生產此類薄膜的主要方法。MOCVD腔體的種類可分為垂直式與水平式兩種，其中水平行星式腔體因為生產之薄膜均勻性相當好且腔體製程條件相較於垂直式腔體較有彈性，成為目前較有潛力的腔體種類。過去數值模擬在腔體零組件設計、製程參數影響以及腔體內熱場設計的貢獻相當大。但由於行星式腔體載盤表面自轉與公轉的速度分佈相當複雜，需要透過重建網格或轉移觀察座標等相當複雜的方法建立數值模型，導致過去行星式腔體的數值模型必須忽略晶圓的行星式運動，而載盤表面之邊界條件使用與實際物理條件有差距的準穩態假設。本次研究的目標為建立以單一函數描述整個行星式腔體載盤速度邊界條件的三維暫態模型，並探討不同晶圓轉速與自轉旋轉方向對流場的影響。;Gallium nitride receives lots of attention in the application of deep ultraviolet, power device and high frequency community device because of the high energy band gap and high electron mobility. Metal organic chemical vapor deposition is an important method to produce GaN thin film. Planetary reactor becomes very popular because the thickness uniformity of the film which is produced by planetary reactor is very well and the process parameter in planetary chamber is wider than other chamber design. Numerical simulation is an important way to study the physical phenomenon in the MOCVD chamber. In the past 20 years, the numerical model of planetary reactor is assumed to be quasi-steady because the velocity boundary condition on the susceptor surface is very complicate. To apply this velocity boundary layer, the mesh of the numerical model needs to be rearranged during the iteration. In most of the planetary reactor numerical model, the wafer is assumed to be static to skip the problem which is caused by the moving wafer. In the is study, a time dependent function is used to describe the velocity distribution on the susceptor surface. By applying this function, the velocity boundary layer can be used without mesh rearrangement. The effects caused by different wafer rotation speed and direction is studied by the model build in this work.
