Lu Xizhao, Jiang Feng, Lei Tingping, Zhou Rui, Zhang Chentao, Zheng Gaofeng, Wen Qiuling, Chen Zhong
College of Mechanical Engineering and Automation, Huaqiao University, Xiamen 361021, China.
Department of Electronic Science, Xiamen University, Xiamen 361005, China.
Micromachines (Basel). 2017 Oct 7;8(10):300. doi: 10.3390/mi8100300.
Laser-induced-plasma-assisted ablation (LIPAA) is a promising micro-machining method that can fabricate microstructure on hard and transparent double-polished single crystal sapphire (SCS). While ablating, a nanosecond pulse 1064 nm wavelength laser beam travels through the SCS substrate and bombards the copper target lined up behind the substrate, which excites the ablating plasma. When laser fluence rises and is above the machining threshold of copper but below that of SCS, the kinetic energy of the copper plasma generated from the bombardment is mainly determined by the laser fluence, the repetition rate, and the substrate-to-target distance. With a lower repetition rate, SCS becomes metallized and gains conductivity. When micro-machining SCS with a pulsed laser are controlled by properly controlling laser machining parameters, such as laser fluence, repetition rate, and substrate-to-target distance, LIPAA can ablate certain line widths and depths of the microstructure as well as the resistance of SCS. On the contrary, conductivity resistance of metalized sapphire depends on laser parameters and distance in addition to lower repetition rate.
激光诱导等离子体辅助烧蚀（LIPAA）是一种很有前景的微加工方法，可在坚硬且透明的双面抛光单晶蓝宝石（SCS）上制造微观结构。在烧蚀过程中，波长为1064 nm的纳秒脉冲激光束穿过SCS衬底并轰击排列在衬底后面的铜靶，从而激发烧蚀等离子体。当激光能量密度升高且高于铜的加工阈值但低于SCS的加工阈值时，轰击产生的铜等离子体的动能主要由激光能量密度、重复频率和衬底到靶的距离决定。在较低的重复频率下，SCS会金属化并获得导电性。当通过适当控制激光加工参数（如激光能量密度、重复频率和衬底到靶的距离）来控制用脉冲激光对SCS进行微加工时，LIPAA可以烧蚀出特定线宽和深度的微观结构以及SCS的电阻。相反，金属化蓝宝石的导电电阻除了取决于较低的重复频率外，还取决于激光参数和距离。
