Cr/GaAs界面的反应特性及电子性质的研究  

Studies of Reaction Characteristics and Electronic Properties at Cr/GaAs Interfaces

作　　者：金高龙[1,2] 陈维德[1,2] 许振嘉[1,2] 

机构地区：[1]中国科学院半导体研究所,北京100083 [2]中国科技大学结构分析中心

出　　处：《Journal of Semiconductors》1991年第5期265-272,共8页半导体学报（英文版）

摘　　要：本文对金属Cr淀积在GaAs(100)清洁表面后引起的界面反应及电子性质的变化作了较详细的研究.我们给出了具体的模型描述初始界面的突发反应过程,分析了突发反应的起因,并认为初始As的析出是造成界面突发反应的一个重要因素.实验结果表明:随着覆盖度θ的增大,Cr2p结合能不断趋向纯金属的结合能,即向较高的结合能方向移动;同时峰形愈来愈对称,即拖尾效应减弱,这与Cr/Si界面Cr的变化规律极其相似,而与通常的过渡金属(TM)在TM/Si界面及 TM/GaAs界面的变化规律不同,显示出Cr特有的变化规律.随着退火温度的升高,Cr/CaAs界面的反应加剧;由于 Cr的内扩散加强,在界面处形成 CrAs,阻挡了As的外扩散,而界面余留的Ga原子随着温度升高外扩散有所增强.The reaction characteristics and electronic properties at Cr/GaAs interfaces during deposi-ting Cr on GaAs(100) have been studied in details.For coverage of θ<2.5A, no chemicalreaction was observed but As out-diffusion occurred slightly and a patch model can be usedto account for this reaction onset when sequentially depositing Cr on GaAs(100).The Asout-diffusion is one of the important factors +o trigger the interface disruption.For θ=0.6A,the Cr2p core level peak shifts 0.30eV to a lower binding energy compared with that of puremetal Cr.Meanwhile,the Cr2p core line shape is widened and of greater asymmetry comparedwith that of pure metal Cr.These peculiar electronic properties compared with that of other3d metals have been discussed taking into account the special electronic structure of Cr. Be-cause of stronger inter-diffusion of Cr and reaction with As at the interface after annealing,As out-diffusion was stopped. However,the out-diffusion of the remainder gallium at the inter-face grew slightly.

关 键 词：金属/半导体 接触面 反应特性 

分 类 号：TN304.01[电子电信—物理电子学]