Abstract: Molecular dynamic simulations are performed to investigate the microscopic process when a Si atom with an incident energy of 0.03eV bombards a Si(001) 2×1 reconstructed surface at 300K using the Tersoff potential.Six different bombarding 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 adatom 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.

Key words: molecular dynamics, dimer, Tersoff potential, potential energy