ZnS薄膜原子层沉积机理的密度泛函理论研究

Growth mechanism of atomic layer deposition of ZnS thin films: a density functional theory study

使用密度泛函方法研究了以二乙基锌(DEZn)和H2S作为前驱体在硅表面原子层沉积ZnS的初始反应机理.ZnS薄膜的原子层沉积包括2个连续的"半反应":即DEZn与H2S"半反应".研究显示:DEZn与H2S"半反应"都经历了一个C2H6消去过程.通过对比在单硫氢基及双硫氢基硅表面上的反应,发现邻位硫氢基的存在有利于前驱体分子的吸附并能够降低反应活化能,这意味着双硫氢基硅表面上的反应是能量上更有利的反应.另外,也发现DEZn"半反应"比H2S"半反应"更容易进行.

Density functional theory was employed to study the growth mechanism of atomic layer dep- osition of ZnS on the silicon surfaces. Both the diethylzinc （DEZn） and the Hz S half-reactions proceed through a C2 H6 elimination mechanism. By comparison with the reactions on silicon surfaces with sin-gle and double-SH sites, we find that the existence of neighboring -SH can facilitate the adsorption of precursors and lower the activation barrier. Also, we find that it is energetically more favorable for the reactions on silicon surfaces with double -SH sites. In addition, calculations show that the DEZn half-reaction is more favorable as compared to the H2 S half-reaction.