MBE[(GaAs)_l(Ga_(1-λ)Al_xAs)_m]_n/GaAS(001)一维超晶格的X射线双晶衍射测量

MEASUREMENT OF MBEC(GaAs)l(Ga1-x)AlxAs)m]n/GaAs (001)ONE-DIMENSIONAL SUPERLATTICE STRUCTURE PARAMETERS BY X-RAY DOUBLE-CRYSTAL DIFFRACTION METHOD

本文着重介绍了MBE[(GaAs)_l(Ga_(1-x)Al_xAs)_m]_n/GaAs(001)一维超晶格的X射线双晶衍射测量方法。根据卫星峰的出现,证明超晶格的存在。基于超晶格的台阶模型和X射线衍射的运动学理论,推导出超晶格多结构参数的计算方法。并对X射线双晶给出的其他信息做了必要的讨论。

The semiconductor superlattice is a sort of new semiconductor materials developed lately.It has been used to make the laser devices, the field effect transistors and the optoelectronic devices. X-ray double-crystal diffraction is a powerful tool that can measure structure parameters of the super lattices, being nondestructive and having the advantage of high precision. In the paper, We applied X-ray double-crystal diffraction method to [(GaAs)1(Ga1-xAlxAs)m]]n/ GaAs(001) one-dimensional super lattices. On the ground of the step structure model and X-ray diffraction kinematics theory, we obtained a series of calculation methods for determining the superlattice parameters. Based on the appearance of the satellite peaks, existence of the superlattices can be confirmed. We can calculate the superlattices period D from the angular distance Ad between different satellite peaks. We can calculate the Al concentration x in the superlattice with relative intensity ratio of the satellite peaks. At last, we can obtain quantum well parameters, such as well width Lz,berrier region width LB and the molecular layer numbers 1 and m.Other informations obtained from the X-ray double-crystal diffraction rocking curves are also discussed.