局域电子态密度的俄歇电子谱分析

ANALYSIS OF LOCAL DENSITY OF STATES BY AES

采集GaAs／Si界面的各个深度剖面的俄歇线形（Augerlineshape），试图获得局域态密度变化的信息。俄歇信号经过小心处理和一系列修正以消除失真，同时俄歇线形分析藉助因子分析（factoranalysis）来进行。发现在界面中两种化学态并存，某些Si原子与As原子健合，并且每个Si原子将有0．3个p电子转移至As原子上，而其他Si原子保持纯Si元素的Si－Si键。由于Si－As成键而使Si的价带顶稍稍位移，局域态密度（LDOS）幅值明显下降。

In order to measure the local density of states on each depth profile of the GaAs/Si interface by AES, the Auger lineshape is carefully processed and the Auger lineshape analysis is performed with the help of factor analysis. A series of corrections to remove the distortion of the peak shape are carried out.There are two chemical states coexisting in the interface. Some of the Si atoms bond with As and transfer 0. 3 P-electron per Si atom to As, and the others will keep the chemical state of pure Si with Si-Si bond.The top of the valence band of Si has a slight shift due to the bonding between Si and As,and the amplitude of local density of states(LDOS) has a significant decrease.