物理氣相傳輸法(Physical Vapor Transport , PVT)是一種利用昇華的方式生長氮化鋁單晶晶體的方法，由於生長過程中的質傳會受到溫場造成的飽和氣壓差影響，因此長晶溫場控制相當重要。本研究將透過數值模擬針對不同坩堝、塗層以及晶種材料分析其對長晶條件之影響。結果顯示石墨內坩堝因為導電率較低，最大熱源分布於外坩堝，而石墨內坩堝的熱源呈現從坩堝底部遞減至上蓋的分布，由於石墨坩堝之導電率較低的關係，使晶種溫度較高於其他材料，可達到較高的長晶速率( 0.05 mm?hr)，然而石墨內坩堝易被鋁蒸氣侵蝕，需要在坩堝表面鍍上保護層防止汙染，模擬結果顯示，坩堝表面塗層材料對晶種表面溫場影響甚微，因此保護層材料使用不會造成晶體扭曲之碳化鉭較佳。最後碳化矽晶種因為不透光的特性，晶種內部的溫度梯度(0.1-0.19 K/cm)比透光的氮化鋁晶種(0.29-24.7 K/cm)來得小，產生熱應力會比較小，不易產生差排，造成在相同功率下，使用碳化矽晶種長晶會較好。;Physical Vapor Transport (PVT) is a method of growing aluminum nitride single crystal crystals by sublimation. Since the mass transfer during the growth process will be affected by the saturation pressure difference caused by the temperature field, the control of the crystal growth temperature field is very important. This study will analyze the influence of different crucibles, coatings, and seed materials on the growth conditions through numerical simulation. The results show that since the graphite inner crucible has low electrical conductivity. The largest heat source is distributed in the outer crucible, while the heat source of the graphite inner crucible decreases from the bottom of the crucible to the lid. Due to the lower conductivity of the graphite crucible, the temperature of the seed crystal is higher than other materials, and a higher crystal growth rate( 0.05 mm?hr) can be achieved. However, the graphite inner crucible is easily corroded by aluminum vapor, and a protective layer needs to be plated on the surface of the crucible to prevent contamination. The simulation results show that the surface of the crucible is coated the layer material has little effect on the surface temperature field of the seed crystal, so it is better to use tantalum carbide that does not cause crystal distortion as the protective layer material. Finally, because of the opaque nature of the silicon carbide seed crystal, the temperature gradient inside the seed crystal (0.1-0.19 K/cm) is smaller than that of the transparent aluminum nitride seed crystal (0.29-24.7 K/cm). The thermal stress generated is relatively small, and it is not easy to produce defects. As a result, it is better to use silicon carbide seed crystals to grow crystals under the same power.
