不同气体环境下532nm激光诱导硅表面形貌的研究

研究了在不同气体环境下，利用532nmNd：YAG纳秒脉冲激光累积辐照单晶硅表面形成的微结构，结果表明，在其他条件相同，背景气体不同的情况下，背景气体对硅表面形貌的形成起着重要的作用。具体分析了真空、N2和SF6 3种环境气氛下形成的微结构，结果显示，在sF6中形成的锥形微结构的数密度比在N2和真空中的大，并且锥形具有更大的纵横比；在N2、真空和sF6中形成的微结构尺寸依次减小。sF6气氛下，激光辅助化学刻蚀的效率比在真空和N2气氛中的高。另外，辐照区域边缘有波纹微结构形成，分析认为，该微结构的形成是由表面张力波的冷却导致的。

Surface morphology of silicon induced by 532nm nanosecond laser under different ambient atmospheres

The micro-structures of single crystal silicon surfaces produced by the cumulative radiation from 532 nm Nd∶ YAG nanosecond laser pulses were investigated under different ambient atmospheres. The results show that the ambient atmospheres have an important role on the silicon surface morphology. The microstructures produced in vacuum, N2 or SF6 were analyzed in detail, it was indicated that the density of the spikes formed in SF6 is larger than those formed in N2 or vacuum, and the spikes have higher aspect ratios than those in other ambient atmospheres. Furthermore, the dimensions of the microstructures formed in N2, vacuum or SF6 have decreased in turn. The experimental results suggest that the efficiency of laser-induced chemical etching in SF6 atmosphere is higher than those in vacuum or N2 atmospheres. Moreover, there are ripple microstructures formed on the edge of irradiation area, which is caused by the frozing of capillary waves.