设计了方形和阶梯状两大类的图形化蓝宝石衬底(PSS), 使用Crosslight公司的工艺软件CSuprem建立了三维的方形和阶梯状两类图形衬底GaN LED器件, 然后使用APSYS软件模拟计算出它们的光电特性。并且对方形图形衬底的刻蚀深度进行了优化, 通过对模拟结果的比较得到刻蚀深度与边长的比值为0.4时, 这种方形图形衬底GaN LED的光提取效率最高, 且比平面衬底提高了20.13%。对阶梯状图形衬底的阶梯层数进行了比较, 发现随着阶梯层数的增加, 光提取效率也随着增加, 阶梯状层数为5时, 光提取效率比平面衬底提高了30.03%。并对方形PSS LED进行了实验验证。

The CSuprem software is applied to help fabricate three-dimensional GaN LED with patterned sapphire substrate (PSS) and the photoelectric characteristics of these GaN LEDs are simulated with APSYS. The ‘square-type’ patterned sapphire substrate and the ‘step-type’ patterned sapphire substrate are designed and optimized. For ‘square-type’ patterned sapphire substrate, the depth of etching is optimized. The light extraction efficiency of GaN LED with this kind of patterned sapphire substrate is highest when the aspect ratio is 0.4, and the light extraction efficiency is improved 20.13% compared with that of GaN LED with conventional sapphire substrate (CSS). For ‘step-type’ patterned sapphire substrate, the number of step is optimized. The light extraction efficiency will increase with the number of steps, and the light extraction efficiency is improved 30.03% compared with that of GaN LED with conventional sapphire substrate (CSS). At last, the experiment is conducted for the ‘square-type’ patterned sapphire substrate demonstration.