Si(100)—As表面钝化作用和氧吸附

Passivation Effect and Oxygen Adsorption of Si(100)-As Surface

利用自己研制的具有分子束外延系统的表面分析联合谱仪研究了氧与Si(100)—As表面的相互作用。本文进一步证实了As层是Si表面的很好的钝化层,并首次研究了Si(100)—As表面的氧吸附全过程。实验表明,氧的饱和覆盖量为0.5单原子层,即Si表面上存在As原子层而使吸附位置减少一半。另外,通过吸附动力学分析得知,Si(100)—As表面的初始粘附系数是5.6×10^(-3),比清洁的Si(100)表面小一个数量级。Si表面上As的钝化作用是Si原子的悬挂键态被As原子的占有孤立对态代替而形成。

The interaction of oxygen with Si(100)-As surface has been studied by a home made combinedsurface analysis spectrometry with MBE system.This paper confirms that As layer isa good passivation film for Si surface and studies the overall process of oxygen adsorption ofthe Si(100)-As surface for the first time.It is shown that the oxygen coverage at saturationhas 0.5 monolayer, i.e., adsorption sites are reduced by half with the existence of As layer.Using kinetic analysis, the initial sticking coefficient for Si(100)-As surface was found to be5.6×10^(-3)which is ten times less than for clean Si(100) surface.The passivation effect of Asatoms on Si surface is interpreted with the existence of lone-pair states instead of danglingbandstates.