稀土金属Tb在GaAs(100)表面的吸附及其界面形成的研究  

Studies of Tb Adsorption on GaAs(100) and Its Interface Formation

作　　者：郭红志[1] 张发培[1] 潘海斌[1] 孙玉明[1] 许保宗[1] 徐彭寿[1] 

机构地区：[1]中国科学技术大学国家同步辐射实验室,合肥230029

出　　处：《真空科学与技术》2000年第2期96-98,共3页Vacuum Science and Technology

摘　　要：利用同步辐射光电子能谱技术研究了Tb/GaAs(10 0 )界面的吸附过程和界面形成。通过对价带谱及高分辨率的Ga,As芯能级谱的研究表明 ,在较低的覆盖度下 (<0 2nm) ,Tb与GaAs衬底的反应很弱 ,形成较突变的金属 /半导体界面。当Tb的覆盖度增加时 ,As 3d和Ga 3d的表面发射峰很快消失 ,Tb与衬底发生反应 ,置换出Ga而与As形成化学键。同时Ga原子会向Tb薄膜内扩散并偏析到表面 ,而Tb As化合物只停留在界面附近区域。当Tb淀积到 0 6nm时 ,Tb膜金属化。Tb adsorption on GaAs(100) surfaces and its interface formation at room temperature were studied with synchrotron radiation photoemission.The valence spectra and high resolution As 3 d and Ga 3 d core levels spectra show that there is a weak reaction of Tb and the substrate at low Tb coverage (<0 2 nm) and the interface is nearly abrupt.The peaks in the spectra originating from As 3 d and Ga 3 d core levels on the surface disappear as Tb coverage increases.This observation indicates that Tb may react with the substrate and replace Ga atoms which,in turn,form chemical bonds with As atoms.We suggest that Ga atoms,at the same time,diffuse into Tb overlay and segregates to the surface,whereas As Tb compounds remain at the interface.When Tb coverage reaches 0 6 nm,Tb overlayer becomes metallic.

关 键 词：铽 砷化镓 界面扩散 半导体 

分 类 号：TN304.23[电子电信—物理电子学]