Distributions of impurity atoms in semiconductors analyzed by X-ray CTR scattering measurement

电子学和光电子学的进一步发展，对材料提出了新的功能要求。因此，已经开始采用诸如量子威尔斯的低维结构。在几个ML厚度的量子结构中，仅几埃尺度的界面的粗糙度不再是可以忽略的。与此同时，决定半导体电子性质的杂质原子的分布也必须在同样的尺度上加以理解。本文提出了用X射线晶体截断棒散射（CTR）测量方法在原子尺度上研究界面原子分布的方法，并对CTR散射进行了详细的模拟，找到了更灵敏地测量杂质原子分布的条件。X射线CTR散射测量需要高强度的X射线来研究杂质原子的分布。我们还尝试开发了一种简单便携的X射线CTR散射测量系统，以便在有高强度X射线源的情况下利用任何机会。在模拟的基础上，利用该测量系统对In原子在GaAs层中的扩散分布进行了测量，验证了该测量系统和方法的可行性，并成功地研究了In原子在GaAs层中的扩散分布。

For a further development of electronics and optoelectronics, new functions of materials are demanded. Thus, low-dimensional structures such as quantum wells have become to be adopted. In the quantum structures of a few ML thicknesses, the vagueness of the interface in the scale of only a few angstrom is no longer negligible. At the same time, the distributions of the impurity atoms which determine the electronic properties of semiconductors must be understood in the same scale. In this work, we proposed that the X-ray crystal truncation rod (CTR) scattering measurement can be used to investigate the distributions of atoms at the interfaces in atomic scale.We had conducted the simulation of the X-ray CTR scattering in detail to find the condition where the distributions of impurity atoms were detected more sensitively. The X-ray CTR scattering measurement need high intensity X-ray to investigate the distributions of impurity atoms. We also tried to develop a X-ray CTR scattering measurement system which was simple and portable in order to utilize any chance when the high intensity X-ray source was available. Based on the simulation and using the measurement system, the distribution of In atoms diffused in the GaAs layer was measured to show the ability of the measurement system and method, and the distributions were successfully investigated.