Development of characterization system for strain distribution at semiconductor heterojunction interfaces

在本研究计划中，我们研究了半导体异质结界面处的界面应力，并发展了一种新的异质界面应力二维分布表征系统。本文主要研究了在GaAs衬底上用液相外延生长InGaAsP/GaAs异质结构和在GaAs衬底上用有机金属气相外延生长ZnSSe/GaAs异质结构两种情况。特别介绍了我们几年前发展起来的一种新的半导体异质结界面应力的表征方法。该方法利用了GaAs晶体中3d过渡金属杂质的发光特性，这种发光特性对杂质周围的应变场非常敏感。利用这一方法，我们研制了一套新的系统，用Ar或Cr离子激光激发，测量了GaAs异质结界面附近的Cr相关发光，并表征了异质结界面应力的二维分布。在这个系统中，我们引入了一个新的光学系统的发光测量。利用该系统，我们研究了InGaP/GaAs和ZnS_xSe_3/GaAs两种半导体异质结<1-x>，获得了异质结界面应力的分布及其来源的信息。

In this research project, we have investigated the interface stress at some semiconductor heterojunction interfaces and developmed a new characterization sysytem for two-dimensional distribution of the heterointerface stress. Here we have studied mainly two cases of InGaAsP/GaAs heterostructure grown on GaAs substrate by liquid phase epitaxy and ZnSSe/GaAs heterostructure grown on GaAs by organometallic vapor hpase epitaxy. In particular, we have introduced a new characterization method for interface stress at semiconductor heterostructures which was developed by ourselves several years ago. This method utilizes the luminescence due to 3d transition-metal impurities in GaAs crystal which is very sensitive to strain field around the impurities. With the use of this method we have developed a new system shich measures Cr-related luminescence in GaAs near semiconductor heterointerfaces by excitation of Ar- or Kr-ion laser and characterizes two-dimensional distribution of the interface stress at heterostructures. In this system we have introduced a new optics system for the luminescence measurements. Using this system developed in this project, we have investigated two semiconductor heterostructures of InGasP/GaAs and ZnS_xSe_<1-x>/GaAs, and obtained information on the distribution of the interface stress at these heterostructures and the origin of such interface stress.