| 摘要: | 半導體薄膜製造一直為全世界製造研究熱點，金屬有機化學氣相沉積法（MOCVD）因具有製造良好均勻度大尺寸薄膜的能力，且兼具高純度，材料變化高等靈活性，為現今LED磊晶產業主要的製程技術，也因為近來LED發展，MOCVD製程目前也具有一定的成熟度。
多數垂直式MOCVD模擬分析的入口邊界採用氣體流出slot後作為入口幾何條件，鮮少探討氣體在腔體上方的分流情形，因此本研究採用有限元素分析軟體，探討流體從單一氣孔和進行入口導流之後作相互比較。本研究設計一套入口導流系統，其系統可分上下兩層導流板，上下兩層分別先進行個別模擬，其中上層部分有進行實驗相互驗證，兩層分別完成之後，最後進行雙層導流模擬，此研究目的為提升導流板出口(腔體入口)處之流速均勻度，進而提升薄膜生長均勻度。
模擬結果顯示，上層導流板之分流角度和下方slot的角度會有一定影響，若是兩分流角度和slot角度相差22.5度會取得最佳的腔體入口流速分佈，此部分結果和實驗結果相互對應。調整slot寬度，可以發現減少slot寬度需要更高的壓力差才能使氣體擴散至腔體內，因而增加腔體入口流速均勻度。下層導流板設計，發現增加六入口設計，可以減少外側slot流速較高的問題，最後調整不同通道和slot寬度比例，可以取得單一slot最佳的流速均勻度。
雙層導流系統，藉由氣體配置模擬，可以發現有機物(TMAl)適合由上層導流板通入，氨氣(NH3)適合由下層導流板通入，套用質傳模擬，增加中間slot設計題生入口下方有機物濃度均勻度，最後進行模模生長模擬，可以發現雙層導流後製造之薄膜均勻度較高，薄膜不均勻度提升至8.8%。
;Semiconductor thin film manufacturing has been a worldwide research hotspot, metal organic chemical vapor deposition(MOCVD) due to the manufacture of good uniformity of large-size film, and both high purity, material changes and high flexibility, which the main process for the current LED epitaxial industry. But also for the development of LED industry in recent years, MOCVD process is also a certain degree of maturity.
Most of the vertical MOCVD analysis of the inlet boundary using gas out of slot as the entrance boundary conditions, rarely discuss the gas flow above the chamber, so this study uses finite element analysis software to comparison with fluid from a round jet, and gas flow after inlet diversion. In this study, a set of inlet diversion system is designed. The system can be divided into two layers, the upper and the lower layers are respectively simulated. Flow simulation, the purpose of this study is to enhance the flow rate uniformity of the chamber inlet, thereby increasing the film growth uniformity.
According to the simulation results, if the diversion angle of upper baffle plate and bottom is 22.5 degrees, the optimal velocity distribution of the chamber inlet is obtained. The results of this part also correspond to the experimental results. By adjusting the slot width, it can be found that reducing the slot width requires a high pressure difference to diffuse the gas into the chamber, thereby increasing the uniformity of the chamber inlet flow rate. The lower baffle design, found to increase the six-entry design, can reduce the lateral slot flow rate higher problem, and finally adjust the different channel and slot width ratio, it can get a single slot the best flow rate uniformity.
For double layer diversion design, it can be found that TMAl is suitable for passing through the upper baffle, and NH3 is suitable for passing through the lower baffle by gas configuration simulation. Apply mass transfer simulation, the results show that uniformity of the film is increased to 8.8% after the double-layer diversion is carried out, and the uniformity of the organic matter is increased. |
