【摘要】 较大的晶格失配和热失配使得异质外延生长的GaN材料具有很高的残余应力，对材料和器件的性能产生重要影响。在蓝宝石衬底和GaN外延层之间插入一层石墨烯，通过Raman光谱和弯曲度测试分析了石墨烯插入层对GaN材料应力的影响。Raman测试结果表明，蓝宝石衬底上GaN材料压应力为0.56 GPa,引入石墨烯插入层后GaN材料压应力为0.08 GPa。弯曲度测试结果表明无石墨烯插入层的蓝宝石上GaN材料弯曲度约为21.74μm,引入石墨烯插入层后弯曲度约为1.39μm,引入石墨烯插入层的GaN材料弯曲度显著降低。讨论了石墨烯插入层对蓝宝石上GaN材料的应力调制机制，验证了石墨烯插入层技术对于异质衬底上获得完全弛豫GaN外延层的可行性。更多还原

【Abstract】 Due to the large lattice and thermal mismatch, the high residual stress in GaN epilayer prepared on foreign substrate enormously influences the performance of materials and devices. A layer of graphene was inserted between the sapphire substrate and the GaN epitaxial layer, and the effect of graphene interlayer on the stress of GaN material on sapphire was analyzed by Raman spectroscopy and bow testing. The Raman characterization results show that the compressive stress of GaN on sapphire with graphene interlayer is 0.08 GPa, compared with the compressive stress of 0.56 GPa of GaN on sapphire substrate. The measurement results shows that the bow of GaN on sapphire with graphene interlayer is about 1.39 μm, compared with about 21.74 μm without graphene interlayer. The bow of the GaN with graphene interlayer decreased significantly. The stress modulation mechanism of graphene interlayer to GaN on sapphire was discussed. It is verified that the graphene interlayer technique is a viable way to obtain fully relaxed GaN epilayer on foreign substrate.更多还原