(1. 云南冶金集团总公司技术中心,昆明 650031;
2. 昆明理工大学 冶金与能源工程学院,昆明 650093;
3. 昆明冶研新材料股份有限公司,昆明 650031)
摘 要: 基于MP2/6-311G(d,p)方法,计算并得到SiCl4锌还原各反应通道上各驻点的几何构型、振动频率和能量。根据密度泛函理论,采用广义密度梯度近似和总体能量平面波赝势方法结合周期性平板模型,研究反应驻点在Si(100)面上的吸附、解离及锌还原过程。结果表明:衬底硅参与SiCl4锌还原反应,SiCl4易在顶位吸附解离成—SiCl3和—Cl自由基;当硅基表面有—Cl自由基吸附时,气相中的Zn原子或硅基面吸附的—ZnCl自由基更容易与—Cl自由基结合,而不是与含氯的硅自由基(—SiCln,n=1~3)结合。
关键字: 多晶硅;密度泛函理论;锌还原;反应机理
(1. The Technique Center of Yunnan Metallurgy Co., Ltd., Kunming 650031, China;
2. Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, Kunming 650093, China;
3. Kunming Yeyan New-Material Co., Ltd., Kunming 650031, China)
Abstract:The channel geometries, vibration frequencies and energy of all stagnations zinc reduction reaction for SiCl4 were calculated through the MP2/6-311G(d, p) method. According to density functional theory, the effects of adsorption, dissociation and zinc reduction of stagnation in the Si(100) surface were studied using the generalized gradient approximation density and total energy plane wave pseudo-potential method combined with periodic slab model. The results show that silicon substrate can participate in zinc reduction reaction of SiCl4, SiCl4 can be absorbed in top sites easily and dissociate into freed radical —SiCl3 and —Cl. When there is —Cl radical adsorbed on the surface of silicon, atom Zn or free radical —ZnCl, which is absorbed on the base silicon, tends to combine with —Cl rather silicon chloride (—SiCln, n=1-3).
Key words: polycrystalline silicon; density functional theory; zinc reduction; reaction mechanisms