用X射线衍射研究缓冲层对GaInAs材料的影响

Study of the Graded Buffer Layer Effect on GaInAs by X-Ray Diffractometer

用分子束外延方法制备了具有GaInAs组分渐变缓冲层和不具有GaInAs组分渐变缓冲层的Ga0.9In0.1As/GaAs结构的外延材料。利用高分辨率X射线衍射法(HRXRD)对制备的两种样品分别进行了测试分析。实验结果表明,GaInAs组分渐变缓冲层对外延生长在GaAs衬底上的Ga0.9In0.1As外延材料的晶体质量具有显著的改善作用,极大降低了由于外延层与衬底晶格不匹配所带来的影响。从X射线倒易空间衍射(RSM)二维图谱结果来看,具有GaInAs组分渐变缓冲层结构的样品,其Ga0.9In0.1As外延层与GaInAs组分渐变缓冲层接近完全弛豫,Ga0.9In0.1As外延层的应变降低,表面残留应力小于0.06%,同时,GaAs衬底与Ga0.9In0.1As外延层之间的偏移夹角明显变小。

Ga0.9In0.1As/GaAs structure samples with and without GaInAs graded buffer layer were grown by molecular beam epitaxy （MBE）. The two samples were tested and analyzed separately by high resolution X-ray diffraction （HRXRD）. The results show that the GaInAs graded buffer layers which were grown on GaAs substrate can dramatically improve the crystal quality of Ga0.9 In0.1 As and greatly reduce the impact due to the epitaxial layer and substrate lattice mismatch. The RSM data show that Ga0.9In0.1As layer relaxed with the substrate with GaInAs degraded buffer layer and the residual strain in the surface is less than 0. 06% and the offset angle of the GaAs substrate with Ga.9In0.1As becomes smaller.