整體長晶系統之熱流模擬研究

Three-Dimensional Global Simulation of Thermal and Flow Fields in Horizontal Zone Melting Crystal Growth System

葉碧純(Bea-Chun Yeh)

指導教授 ： 藍崇文

國立臺灣大學/工學院/化學工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.01864

摘要

溫場決定晶體的生長界面，影響晶體品質及長速最為關鍵，所以良好的熱場設計是很重要的。本論文建立一套數值模式來模擬水平區熔法整體長晶系統之熱場與流場，此數值模式為two-level model，稱為雙層模式，包含整體模式與局部模式。在整體模式方面，包含整體長晶系統，將以商用計算流體力學軟體(CFD)來處理，可以處理包含整體溫場、氣相對流與三維面對面熱輻射，計算所得到的溫場將帶入局部模式當邊界條件。而局部三維自由面熱流模擬，只包括坩堝、進料、晶體與熔液部分，以本實驗室自行開發的多重網格有限體積法(FVM/MG)來達成，此部分可以計算熔液對流、整體熱傳與固液界面的變形等，所計算的變形固液界面與表面溫度可帶回整體模式當作邊界條件，如此來回運作直到溫場收斂為止。另外我們也探討氣相流動對整體溫場的影響。最後我們針對會固液界面形狀影響的因素作探討，提出對實驗的建議。結合此雙層模式，可以有效了解整體熱場分布與固液界面的變形，對熱場設計十分有幫助。

關鍵字

水平區熔法 ； 流場 ； 熱場

並列摘要

The hot zone design is the most important task to decide the growth interface, the quality of the crystal and the growth rate. A computational model has been developed to simulate the three-dimensional global thermal and flow fields in horizontal zone melting crystal growth system. The method is so called “ two-level model”, which includes global model and local model. The global model includes the whole crystal growth system. We use the commercial Computational Fluid Dynamics software to combined convection/conduction/surface-to-surface radiation calculations. The melt convection and growth interface calculations in the local model are then made by the an efficient Finite volume method using multigrid acceleration within ampoule, feed, crystal, and melt, with the boundary conditions supplied by the global model simulations. The growth interface shape can be modified in the next global model simulation. The backwards and forwards calculations can be carried out until the thermal fields convergence. We also discuss the effects of gas flow on the global thermal fields and interface shape. Finally, we discuss some influences on the interface shape. To combine the two-level model can be efficient to analyze the global thermal fields and interface shape and it is helpful to design the hot zone in crystal growth system.

並列關鍵字

melting ； flow fields ； horizontal zone ； thermal fields

參考文獻

2. G. Müller, J. Friedrich, J. Crystal Growth 266 (2004) 1

3. F. Dupret, P. Nicodeme, Y. Ryckmans, P. Wouters, and M. J. Crochet, Int. J. Heat Mass Transfer 33 (1990) 1849

6. R. Assaker, N. van den Bogaert, F. Dupret, J. Crystal Growth 180 (1997) 450.

11. M. Neubert, P. Rudolph, Prog. Crystal Growth Characterizat. Mater. 43 (2001) 119.

14. G.Müller, B. Birkmann, J. Crystal Growth 237–239 (2002) 1745.