直接固化法因成本低且製造過程簡單，是生產多晶矽晶錠最常用的方法。 近幾年來DSS法已發展成可生產大尺寸多晶矽晶錠，因此有必要藉由模擬 將爐體設計做優化改善，提升多晶矽晶錠之品質。 本研究使用有限體積法(FVM)進行多晶矽生長過程的暫態數值模擬，主要探討溶湯中的熱流場、固液界面形狀以及氧、碳雜質的分佈。模擬所使用之G6、G8爐體尺寸大小、材料性質、加熱器輸出功率以及絕緣層的開度均採用矽晶公司實際生長晶錠時所量測到的數據。 在G6爐體優化方面，將石墨層側邊挖空一半並置換為絕緣塊材料，可降低靠近坩堝壁區域固液界面凹率，使固液介面形狀更為平坦。在爐體內部加裝導引氬氣流動之導流板，可增加靠近自由液面處的流速，降低氧、碳雜質濃度。修改爐體之支柱設計，將支柱數目與中心距離作調整並加大支柱直徑，可使軸向溫梯增加，晶錠固化時間縮短，使碳雜質濃度減少。將以上幾種修改設計結合絕緣塊與保溫塊做成一整合型爐體，可使固液界面形狀平整度增加、大幅降低氧與碳雜質濃度，並減少加熱器功率的消耗，有助於提升多晶矽晶錠的品質。 在G8爐體與G6爐體的比較中，可發現G8爐體的固液界面形狀更為平整，並且氧、碳雜質的濃度差異不大，顯示G8爐體在未來能具有相當大的優勢。 將G8爐體內部增加絕緣塊與保溫塊，可增加軸向溫度梯度，使固液界面維持微凸的形狀，有利於晶體的生長，此外可減少加熱器的輸出功率，達到節能的效果。 ;Directional Solidification method (DSS) is a simple method to produce the ingots and it has low cost. So this method is the most commonly used to growth the mc-si ingots. In recent years, DSS method can produce the large size mc-si ingots. Therefore, it is necessary to optimize the furnace structure to improve the mc-si ingots quality. In this study, we used FVM method transient numerical simulation to investigate the distribution of the thermal flow field, interface shape, oxygen and carbon impurities distribution in the melt. The experimental data such as G6 and G8 furnace size, material, heater power consumer and insulation height are provided by company. In the G6 furnace optimization, I removed a half side graphite layer and replaced as an insulation block. It can decrease the interface shape concave near the crucible region. The interface shape will be more flat. Add the deflector to guide the argon gas flow in the furnace can increase the velocity of flow near the free surface. It can significantly reduce the concentration of oxygen and carbon. Enlarge the volume of supports and change the distance between supports and the center point of the furnace can increases the axial temperature gradient and the ingot solidify time will be reduce, it can also reduce concentration of carbon. Combine these several designs and add the insulation block to make the furnace can get these several advantages and decrease the heater power consumer. The ingot quality can be increase. Compare G6 and G8 model, we can find G8 furnace interface shape is more flat, concentration of Oxygen and carbon are little difference. It means G8 furnace will be a better superiority in the future. Add the insulation block in the G8 furnace can increases the axial temperature gradient. The interface shape become little convex, it is favorable crystal growth. Further can reduce the power consumer of the heater, achieve the energy saving effect.
