低能入射Si与Si(001)2×1重构表面相互作用过程的分子动力学模拟

Molecular Dynamic Simulation of the Interaction Between a Low Energy Bombarding Si Atoms and the Si(001)2×1 Reconstructed Surface

利用Tersoff势函数,对300K时初始入射动能为0.03eV的单个Si原子从6个不同位置轰击Si(001)2×1重构表面的动力学过程进行了模拟.分析了入射Si原子的动能变化、势能变化以及其运动轨迹.结果表明:入射原子与表面原子相互作用几个皮秒后即可进入稳定位置,其与基底原子的结合能最大可以达到2.99eV;从位置1,2,3,4入射的原子不能使基底表面的二聚体键断开,而从位置5和位置6入射时,表面二聚体键的断开在入射原子与基底表面原子发生相互作用几十飞秒后即可完成.

Molecular dynamic simulations are performed to investigate the microscopic process when a Si atom with an inci- dent energy of 0.03eV bombards a Si（001） 2×1 reconstructed surface at 300K using the Tersoff potential. Six different bom- barding sites are chosen in order to study the interaction between the bombarding Si atom and substrate surface atoms. We map the bombarding Si atom＇s kinetic energy,potential energy and trajectory. The results show that the interaction between the bombarding Si atom and the substrate surface atoms completes in a few picoseconds. The max binding energy of an ada- tom to a Si（001） 2 × 1 reconstructed surface is about 2.99eV. A single,0.03eV incident Si atom can open a surface dimer in dozens of femtoseconds after the interaction takes place from positions 5 or 6,while the atom bombarded from positions 1,2, 3,4 cannot.