蓝宝石/SiO2/AlN/GaN多层结构表面热应力仿真分析

摘要

In order to research the surface thermal stress in Sapphire/SiO2/AlN/GaN epilayer and the stress influence factors, the surface stress in materials with diameter of 40mm were respectively calculated and studied by the finite element modeling method, and the rationality of the model was proved. The epilayer stresses in the radial and axial direction were analyzed. The results indicated that the epilayer stress was uniformin the radial direction. The epilayer surface thermal stress was in direct proportion to growth temperature during the temperature from 400℃ to 1200℃. The dependence between the epilayer surface thermal stress and different parameters were respectively analyzed including growth temperature,SiO2 and AlN transition layers thickness and Sapphire substrate thickness. The results are helpful for study on new technology of epilayers growth and establishing the quality choice standard of low stress epilayer.%为了研究蓝宝石/SiO2/AlN/GaN光阴极组件外延片热应力分布及影响因素,以直径d为φ40 mm的GaN外延片为研究对象,利用有限元分析法对其表面热应力分布进行了理论计算和仿真,验证了仿真模型的合理性.分析了外延片径向和厚度方向的应力分布,结果显示:在1200℃的生长温度下,径向区域内的热应力分布比较均匀,热应力变化范围为±1.38%;生长温度在400℃到1200℃范围内,外延层表面应力与生长温度呈近似正比关系.分析了外延片生长温度、蓝宝石衬底和SiO2、AlN过渡层厚度对表面热应力的影响.研究成果可为该类外延片生长工艺研究和低应力外延片的筛选标准制定提供借鉴.