Nd:YAG纳秒激光诱导硅表面微结构的演化

利用Nd:YAG纳秒激光(波长为532和355 nm)对单晶硅在真空中进行了累积脉冲辐照,研究了表面微结构的演化情况.在激光辐照的初始阶段,532和355 nm激光脉冲均在硅表面诱导出了波纹结构,后者辐照硅表面后形成了近似同心但稍显混乱的环形波纹结构.随着脉冲数的增加,波纹结构逐渐演化为一种类似珠形的凹凸结构,最后形成准规则排列的微米量级锥形结构,该微结构的生长依赖于表面张力波和结构自组织.分析发现,形成的交叉环形结构主要是在355 nm激光辐照硅的过程中,表面张力波导致波纹结构部分叠加的结果.

Evolution of silicon surface microstructure induced by Nd:YAG nanosecond laser

We investigate the evolution of surface microstructure created on single crystal silicon wafer by irradiation of cumulative Nd:YAG nanosecond laser pulses (wavelength 532 or 355 nm) in vacuum. The wavy structures are formed on silicon surface by 532 or 355 nm laser on early stage of laser pulse irradiation, and nearly concentric but slightly disordered semi-circular rings are formed under 355 nm laser pulse irradiation. With the number of laser pulses increasing, the structures gradually evolved into the concave-convex structures which are similar to the beads. And finally quasi-ordered arrays of conical spikes are formed. The growth of these microstructures depends on the capillary waves and self-organization of structures. We find that the cross-ring structures are caused by the superposition of some wavy structures created by capillary waves in the process of 355 nm laser pulses irradiation.