本研究目的在於以模擬觀點建立一碳化矽晶體長晶系統，透過先行模擬計算瞭解長晶爐體內部之物理現象並提出改善方案，以減少不必要的實驗成本。本研究採物理氣相傳輸法（Physical vapor transport, PVT）模擬碳化矽晶體生長，由於物理氣相傳輸法之坩堝內部高溫低壓的密閉狀態且長晶腔內的溫度及氣氛傳輸難以經由實驗直接測量，因此利用電腦輔助設計(Computer aided design, CAD)作為分析爐體的工具是一項有效的解析途徑。
碳化矽長晶系統現象包含電磁加熱、熱場分佈、氣氛濃度分佈以及在晶種層上的長晶行為。藉由數值方法模擬碳化矽生長製程中的熱場及氣氛傳輸進而計算晶種的長晶行為，同時分析石墨坩堝內部之物理現象提出優化方針以達到長晶最佳化(Optimization)之條件。
本研究另一項目標基於技術已經相當成熟的4吋碳化矽長晶系統，在模擬其擴晶的過程中導入一協助改善熱場和氣氛傳輸的氣流導引部件(Cone-shaped structure)於長晶腔中。本研究針對六組不同的坩堝導引構型模擬其熱場、氣氛濃度分佈與長晶速率分佈並進一步對晶體形貌、熱應力與缺陷進行定性的預測，藉此給出較理想的坩堝構型，以達成碳化矽晶體擴晶與降低晶體缺陷的關鍵模擬技術。

Modeling of SiC growth is considered important for the design of crucible structure and the efficiency of experiment process. This paper shows that the growth rate profile of SiC bulk crystal grown by physical vapor transport process depends strongly on crucible structure due to the variation of temperature field and species concentration distribution in growth chamber via simulation technique. The current paper aims at studying growth rate profile with different crucible structure designs by demonstrating each temperature field, species concentration distribution in the growth system. Proper crucible design can optimize the growth rate distribution which may avoid the formation of thermal stress and defects in an as-grown SiC crystal.
To test how crucible structure affect crystal growth, six types of cone-shaped structure have been introduced into growth chamber and calculated the temperature field, concentration distribution and growth rate profile in our simulation. Numerical calculation is conducted by commercial simulation software, COMSOL Multiphysics based on finite element method (FEM), to build up PVT process for our SiC crystal growth simulation.
In this study, the growth rate resulted from different crucible structures are presented based on simulation results. Hence, the favorable crucible structures are given out to predict crystal shape and improve crystal quality.

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