Effect of Substrate Surface Microstructure on the Metalorganic Molecular Beam Epitaxy (MOMBE) Growth of Zinc Selenide on the (100) Face of Gallium Arsenide

该项目的目标是全面描述硒化锌（ZnSe）在砷化镓（GaAs）（100）表面外延层生长的表面化学现象，并发展表面化学、薄膜结构和界面性质之间的关系。研究了GaAs（100）衬底表面重构对金属有机分子束外延（MOMBE）外延ZnSe薄膜生长的影响。利用程序升温解吸和高分辨率电子能量损失能谱（HREELS）研究了二甲基锌、二乙基锌和二乙基硒在富砷的c（4x4）和c（2x8）重构和近化学计量（1x6）重构上的吸附和反应。这些结果与先前富镓（4x1）重构的研究结果进行了比较。利用原子力显微镜和扫描隧道显微镜研究了GaAs（100）衬底重构和工艺条件（温度、压力等）对ZnSe薄膜形貌和表面结构的影响。利用HREELS和非线性光谱学对ZnSe/GaAs界面的结构和电子特性进行了研究。本项目所研究的特定耦合器可用于二极管、led、激光器和其他光电器件。加工技术的改进应会扩大其用途。此外，这项工作的大部分可以推广到其他II-VI / III-V异质结。

9321341 Vohs The objectives of this project are to provide a comprehensive description of the surface-chemical phenomena involved in the growth of epitaxial layers of zinc selenide (ZnSe) on the (100) surface of gallium arsenide (GaAs) and to develop relationships between surface chemistry, film structure, and interfacial properties. The influence of surface reconstruction of a GaAs(100) substrate on the growth of epitaxial ZnSe films using metalorganic molecular-beam epitaxy (MOMBE) is studied. The adsorption and reaction of dimethylzinc, diethylzinc, and diethylselenium on the arsenic-rich c(4x4) and c(2x8) reconstructions and the nearly stoichiometric (1x6) reconstruction of GaAs(100) are investigated using temperature-programmed desorption and high-resolution electron-energy-loss spectroscopy (HREELS). These results are compared with those from previous studies on the gallium-rich (4x1) reconstruction. The morphology and surface structure of ZnSe films are characterized using atomic force microscopy and scanning tunnelling microscopy as functions of GaAs(100) substrate reconstruction and processing conditions (temperature, pressure, etc.). Structure and electronic properties of ZnSe/GaAs interfaces are probed using HREELS and nonlinear optical spectroscopies. The specific couple studied in this project is used in diodes, LEDs, lasers, and other optoelectronic devices. Improved processing techniques should lead to expanded uses. Additionally, much of this effort may be generalizable to other II-VI / III-V heterojunctions.