Development of characterization system for strain distribution at semiconductor heterojunction interfaces

在本研究项目中，我们研究了一些半导体异质结界面的界面应力，并建立了一种新的异质结界面应力二维分布表征体系。本文主要研究了液相外延法在GaAs衬底上生长InGaAsP/GaAs异质结构和有机金属气相外延法在GaAs衬底上生长ZnSSe/GaAs异质结构两种情况。特别地，我们介绍了我们几年前开发的一种新的半导体异质结构界面应力表征方法。该方法利用了砷化镓晶体中三维过渡金属杂质对杂质周围应变场非常敏感的发光特性。利用这种方法，我们开发了一种新的系统，该系统在半导体异质界面附近的GaAs中，通过Ar或k离子激光激发来测量cr相关发光，并表征了异质结构界面应力的二维分布。在该系统中，我们介绍了一种用于发光测量的新型光学系统。利用本项目开发的系统，研究了InGasP/GaAs和ZnS_xSe_<1-x>/GaAs两种半导体异质结构，获得了这些异质结构界面应力的分布和界面应力的来源。

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.