OH-在Si(100)面上的吸附与脱附作用机理

利用高斯98中的Hartree-Fock(HF)方法研究了OH-与Si(100)面的吸附和脱附作用机理,计算了OH-在Si(100)面三种(顶位,桥位,穴位)典型吸附位的吸附反应势能曲线,在每个吸附位上根据空间位阻最小和最佳成键方向考虑了OH-垂直进攻和倾斜进攻.结果表明: OH-在进攻三种吸附位时的活化能为零,顶位倾斜吸附最稳定,穴位吸附最不稳定.在顶位倾斜吸附位上Si原子被OH-拉出的反应活化能为1.01 eV,整个吸附脱附过程的活化能为3.29 eV.

OH- adsorption and desorption mechanism on Si(100) surface

Adsorption process and desorption process of OH- on Si(100)surface were analyzed using Hartree-Fock module in Gaussian 98 package.In the calculation OH- attacks in direct and tilted way at three possible positions(top,bridge,hollow)on Si(100)surface.Meanwhile,at every specified site it is kept in the least steric hindrance and in the most favorable bonded direction.Calculations show that the most favorable position is the top silted site,the last is the hollow site.Calculations of the reaction energy curves of the attacking process of OH-towards Si(100) surface show that the activation energy is about 0,and the activation energy for the process of a single Si atom being pulled away from the top tilted site by OH-is about 1.01 eV,and the activation energy of the whole process containing adsorption and desorption is about 3.29 eV.