摘要
利用同步辐射光发射研究了Ｓｍ／ＧａＡｓ（１０）界面形成．高分辨的芯能级谱结果表明，在低覆盖度下（＜０．１ｎｍ），Ｓｍ与衬底的作用较弱，形成较突出的金属／半导体界面．当Ｓｍ的覆盖度增加时，Ａｓ和Ｇａ的表面发射峰很快消失，表明Ｓｍ与Ｇａ发生置换反应而与Ａｓ形成化学键．同时，Ｇａ原子会向Ｓｍ膜体内扩散且偏析到Ｓｍ膜表面，而Ａｓ－Ｓｍ化合物只停留在界面区域．当Ｓｍ膜厚度达到０．５ｎｍ时，Ｓｍ膜开始金属化．结合理论模型，文中还详细地讨论了界面形成和界面结构．
Abstract Synchrotron radiation photoemission has been used to study the room temperature formation of the Sin/GaAs(100) interface. High resolution core level spectra results show that at low Sin coverage(<0.1nm), the interaction between Sm and the substrate is weak, and the interface is nearly abrupt. With increasing the Sm coverage, the surface components of As3d and Ga3d core levels disappear quickly, which indicates Sm can exchange the Ga in bulk GaAs and bond with As. Ga atoms exchanged by the Sm atoms may diffuse into Sm overlayer and segregate on the Sm overlayer, and the As-Sm compounds may remain near the interface. At Sm coverage of 0. 5nm, the Sm becomes the metallic film. According to a theoretical model, the interface formation and the profile are discussed in detail in the text.
基金
国家自然科学基金
中国科学技术大学青年科学基金
