Low Temperature Growth and Surface Chemistry of Strained Germanium Films on Silicon(100)

这项研究涉及的基本问题， 异质外延锗薄膜的生长和表征 在具有（100）取向的晶体硅衬底上， 显示出2 × 1的表面重建。 最近的理论和 实验研究已经支持了 锗/硅系统的电子能带结构， 从改变原子的应变和超晶格组成 规模 这个小组已经发现了假晶域的证据， 在室温下生长的硅上的锗膜。 现在 建议研究薄锗膜的结构， 在低温下生长的硅， 温度 这项工作涉及一个独特的分析组合， 技术：传输离子通道，扫描隧道 低能量电子衍射和俄歇电子 谱 第二个重点将涉及表面化学 应变锗上的吸附原子。 希望人们能分辨出 化学、几何学和应变所起的不同作用， 确定吸附原子的键合位置。 最初，锡和 硫将用作吸附原子。

This research is concerned with fundamental problems involving the growth and characterization of thin heteroepitaxial germanium films on crystalline silicon substrates with a (100) orientation which exhibits a 2 x 1 surface reconstruction. Recent theoretical and experimental studies have given support for dramatic changes in the electronic band structure of germanium/silicon systems resulting from changing the strain and superlattice composition on an atomic scale. This group has found evidence for pseudomorphic domains in germanium films on silicon grown at room temperature. It is now proposed to investigate the structure of thin germanium films on silicon grown at low temperatures and also as a function of temperature. This work involves a unique combination of analytic techniques: transmission ion channeling, scanning tunneling microscopy, low energy electron diffraction, and Auger electron spectroscopy. A second emphasis will involve the surface chemistry of adatoms on strained germanium. It is hoped one can distinguish the seperate roles played by chemistry, geometry, and strain in determining the bonding site of the adatom. Initially tin and sulfur will be employed as adatoms.