UHV/CVD外延生长SiGe/Si表面反应动力学

利用 Si H4 和 Ge H4 作为源气体 ,对 UHV/CVD生长 Si1- x Gex/Si外延层的表面反应机理进行了研究 ,通过 TPD、RHEED等实验观察了 Si( 1 0 0 )表面 Si H4 的饱和吸附、热脱附过程 ,得出 Si H4 的分解应该是每个 Si H4 分子的 4个 H原子全部都吸附到了 Si表面 ,Si H4 的吸附率正比于表面空位的 4次方 ,并分析了 Ge H4 的表面吸附机制 .在此基础上建立了 UHV/CVD生长Si1- x Gex/Si的表面反应动力学模型 ,利用模型对实验结果进行了模拟 ,二者符合得很好

Surface Reaction Mechanism of SiGe/Si Growth by UHV/CVD

The surface reaction mechanism of Si 1-x Ge x/Si growth using SiH-4 and GeH 4 in UHV/CVD system is studied. With the help of TPD(Temperature Programmed Deposition) and RHEED growth, the saturated absorption and desorption of SiH-4 from Si(100) surface is investigated. It is found that all the 4 hydrogen atoms of one SiH-4 molecule are absorbed to the Si surface, which means that the dissociated adsorption ratio is proportional to the fourth power of surface vacancies. The reaction of GeH-4 is also analyzed. Based on these studies, a new surface reaction kinetic model on Si 1-x Ge x/Si epitaxial growth under UHV conditions by SiH-4/GeH-4 is proposed. The prediction of the model fits the experimental results very well.