组分过冲对InP基InAlAs递变缓冲层的影响(英文)

Effects of compositional overshoot on InP-based InAlAs metamorphic graded buffer

通过在InP基InxAl1-x As递变缓冲层上生长In0.78Ga0.22As/In0.78Al0.22As量子阱和In0.84Ga0.16As探测器结构,研究了缓冲层中组分过冲对材料特性的影响.原子力显微镜结果表明,在InAlAs缓冲层中采用组分过冲可以使量子阱及探测器样品表面粗糙度都得到降低.对于相对较薄的量子阱结构,X射线衍射倒易空间扫描图和光致发光谱的测量表明,使用组分过冲可以增加弛豫度、减小剩余应力并改善光学性质.而对于较厚的探测器结构,X射线衍射和光致发光谱测试发现使用组分过冲后的材料性质没有明显的变化.量子阱和探测器结构的这些不同特性需要在器件设计应用中加以考虑.

In0.78Ga0.22As/In0.78Al0.22 As quantum wells and In0.84Ga0.16As photodetctor samples have been grown on InP-based InxAl1-xAs metamorphic graded buffers to investigate the effects of compositional overshoot on the material characteristics.Atomic force microscopy results show that the surface roughness is reduced by the compositional overshoot in the InAlAs buffer layers for both the quantum well and photodetector samples.In the case of thin quantum wells,X-ray diffraction reciprocal space mapping and photoluminescence measurements show that the use of compositional overshoot can increase the relaxation degree,reduce the residual strain and improve the optical quality.While in the case of thicker photodetectors,no obvious improvement is observed after using compositional overshoot.The different behaviours of the metamorphic quantum wells and photodetectors should be considered in the device applications.