论文部分内容阅读
分别在空气和SF6环境下,使用波长为1064 nm的半导体微秒脉冲激光器扫描辐照单晶Si制备出微米量级的硅表面微结构,并利用扫描电子显微镜和可见—近红外分光光度计观测激光辐照后的硅表面形貌和光学特性。结果表明,当硅表面每激光光斑面积累积辐照的微秒脉冲数达到1600个,即可在硅表面形成平均高度为30μm、数密度约为3.0×105spike/cm2的锥形微结构;硅表面在SF6气氛中形成的微结构表面光滑,纵横比为2,而空气中的微结构表面粗糙,纵横比为1,表明SF6气氛更有利于锥形微结构形成;微秒激光辐射后的硅在0.2~2.5μm波段内反射率大幅下降,空气中制备的微结构硅平均反射率10%,SF6中制备的低至2.8%;还探讨了硅表面形貌的演化过程,认为激光辅助化学刻蚀和再沉积机制对于微秒激光诱导硅表面微结构的生长起着重要作用。
The microstructures of silicon surface on the order of micrometers were prepared by scanning and irradiating single crystal Si with a semiconductor microsecond laser at a wavelength of 1064 nm in air and SF6 respectively. The microstructure was observed by scanning electron microscopy and visible-near-infrared spectrophotometer Silicon Surface Morphology and Optical Properties after Laser Irradiation. The results show that when the number of microsecond pulses accumulated per laser spot area reaches 1,600 on the surface of silicon, a conical microstructure with an average height of 30μm and a density of about 3.0 × 105spike / cm2 can be formed on the surface of silicon. The surface of microstructure formed in SF6 atmosphere is smooth with an aspect ratio of 2, while the microstructure in air is rough with an aspect ratio of 1, which indicates that SF6 atmosphere is more conducive to the formation of tapered microstructure. The reflectivity decreases sharply in the wavelength range of 0.2-2.5μm, the average reflectivity of microstructured silicon prepared in air is 10%, and the content of SF6 is as low as 2.8%. The evolution of silicon surface topography is also discussed. It is considered that laser assisted chemical etching And redeposition mechanisms play an important role in the microsecond laser-induced growth of silicon surface microstructures.