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用动力学Monte Carlo模拟方法研究了GaAs(001)邻晶面的外延生长机制.Ehrlich-Schwoebel势垒对邻晶面外延机制有重要的影响.模拟结果显示,低温下Ehrlich-Schwoebel势垒几乎能完全阻止原子向下一台阶面的迁移,高温下原子已能有效地克服势垒的影响并向下一台阶面迁移.在外延生长初期,原子几乎在台阶面上均匀分布.当表面覆盖度达到一定数量后,台阶成核开始.而由于Ehrlich-Schwoebel势垒的存在,在台阶的上侧台阶面上开始有原子的积累,而如果没有Ehrlich-Schwoebel势垒,台阶上侧台阶面上的原子也能被有效地耗尽.Ehrlich-Schwoebel势垒对邻晶面上的外延生长模式有显著的影响,将明显提高达到台阶生长模式的温度.
The mechanism of epitaxial growth of GaAs (001) orthorhombic planes has been studied by the kinetic Monte Carlo simulation method. The Ehrlich-Schwoebel barrier has an important effect on the orthorhombic surface epitaxy. The simulation results show that the barrier of Ehrlich-Schwoebel almost can Completely prevent the migration of atoms to the next step, the atom has been able to effectively overcome the barrier effect of high temperature and migration to the next step in the initial stage of epitaxial growth, the atoms are almost uniformly distributed in the step surface when the surface coverage reached After a certain amount of nucleation, the nucleation of the step starts, and due to the existence of the Ehrlich-Schwoebel barrier, atoms accumulate on the upper step of the step, whereas in the absence of the Ehrlich-Schwoebel barrier, the atoms on the upper step Can also be effectively depleted.The Ehrlich-Schwoebel barrier has a significant impact on the epitaxial growth mode on the adjacent crystal plane, will significantly increase the temperature to reach the step growth mode.