Atomic and Electronic Properties of Compound Semiconductor Surfaces and their Interfaces with Metals

本文对分子束外延(MBE)制备的几种低指数和高指数砷化镓表面的原子几何和电子结构进行了深入的研究。利用分子束外延生长的表面进行结构、成分和能带弯曲的原位探测，将加强对表面重建机制和表面不稳定性的研究，遇到一些高指数表面。低温(LT=70-100oK)肖特基势垒形成的研究将继续进行。在金属聚集、化学反应和互扩散被抑制的这些界面上获得的结果首次表明，必须引用几个独立的机制来解释n型和p型样品的钉扎，这些机制受到温度的不同影响。这项工作将通过研究砷化镓和活性过渡金属之间在低温下形成的界面来扩展。这项研究将包括低温界面形态、原子几何、反应速度和费米能级钉扎的完整表征。对过去三年中发现的结果进行概括，可望对目前的肖特基势垒模型产生重大影响，并对微电子工业具有重要意义。

This is an indepth study of the atomic geometry and electronic structure of several low and high index gallium arsenide surfaces prepared by molecular beam epitaxy (MBE). The use of MBE-grown surfaces with in-situ probing of structure, composition, and band bending will enhance the work on surface reconstruction mechanisms and surface unstabilities, encountered with some high- index surfaces. The investigation of Schottky barriers formation at low temperature (LT=70-100oK) will be continued. The results obtained on these interfaces where metal clustering, chemical reactions and interdiffusion are inhibited, are the first to suggest that several independent mechanisms, diversly affected by the temperature must be invoked to explain pinning on n- and p- type samples. This work will be extended by studying interfaces formed at low temperature between gallium arsenide and reactive transition metals. This study will involve complete characterizations of low temperature interface morphology, atomic geometry, rate of reaction, and Fermi level pinning. A generalization of the results found during the past three years could be expected to have a substantial impact on current models of Schottky barriers and be of importance to the microelectronic industry.