脉冲重复频率对脉冲激光沉积薄膜的生长过程的影响

脉冲重复频率在脉冲激光沉积技术中起重要的作用,影响最终的薄膜材料的性能。利用动力学蒙特卡罗方法,我们研究了脉冲激光沉积技术中,在不同脉冲重复频率条件下的薄膜生长的初期阶段。模拟结果显示,在低脉冲频率时,前后脉冲之间的间隔时间较长,生长岛有足够的时间熟化。因此,生长岛的密度会比较小且岛的形貌比较规则。而当脉冲重复频率增大时,岛的密度则随之增加,岛呈现出松散的或者枝杈状的形貌。另外,脉冲占空比也就是沉积时间在一定程度上也会对岛的凝聚过程有影响。最后我们将模拟结果与实验结果进行了对比和讨论。

Effect of Pulse Repetition Rate on Film Growth in Pulsed Laser Deposition

Pulse repetition rate plays an important role in pulsed laser deposition (PLD) technique, which has been shown to have an influence on final material properties. Using kinetic Monte Carlo method, we simulated the early stage of film growth with varying pulse repetition rate in pulsed laser deposition process. The simulation results display that at a low pulse repetition rate increase, there is such a longer pulse interval that islands are given more time to ripen. As a result, the total of island density reduces and film aggregation tends to compact shape. Island density will increase with pulse repetition rate increase, and islands may be in dispersed or dendritic mode. Duty cycle, that is, deposition time also can effect on islands aggregation to a certain extent. The obtained results have been compared with some experimental data.