在本論文中，我們使用TracePro光學模擬軟體其中的蒙地卡羅追跡法建立出LED之光學模型，探討在不同的基板下，切削角度對於GaN LED之光萃取效率的影響。結果顯示SiC封膠後，60度的切削角度光萃取效率可高達52.54%。另外，進一步利用表面結構之薄型氮化鎵Thin GaN，分析當表面微結構陣列之圓錐的角度改變時，其對於晶片之指向性和光萃取效率的提升幅度，結果指出封膠後圓錐微結構半角為65度時，光萃取效率可達81.16%。

In this thesis, we build the optical model by TracePro based on Monte Carlo ray tracing method. Under different substrate in GaN LED, we analyze the light extraction efficiency (LEE) with different chip shaping angles. In the case of the SiC-based GaN LEDs, the slanted angle in 60°, with lens encapsulation, the LEE reaches 52.24%. Furthermore, we analyze the enhancement of the directionality and the LEE when the slanted angles of the cone array are different by changing surface texture of Thin GaN LED. In the case of Thin-GaN LEDs with diffuse reflector, the slanted angle of 65°with lens encapsulation, where the LEE reaches 81.16%.

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