Yuan Dong-qing, Zhou Ming, Cai Lan, Shen Jian
Center for Photo Manufacturing Science and Technology, Jiangsu University, Zhenjiang 212013, China.
Guang Pu Xue Yu Guang Pu Fen Xi. 2009 May;29(5):1209-12.
Femtosecond laser micromachining of film is an emerging technology for fabrication of MEMS devices. A Ti: sapphire laser (130 fs, 1000 Hz)was used to irradiate the thin film with variations in process parameters such as pulse energy. The film thickness is about 4 microm which was measured by AFM. When we used single pulse to excite the film, the ablation diameter increased along with the energy ascending; when the energy of single pulse was invariable, the diameter had little change when altering the number of pulses. The single pulse threshold fluence of Au film was Fth = 0.7 J x cm(-2) at this ultrashort pulse-length in air. By changing the energy of excitation pulse it was found that when the energy was lower than the threshold, the line on the film was heaved; when the energy was higher than the threshold, the line was concave, which was detected by AFM. It was also found that the width of line decreased along with the increase in process speed when the pulse energy remained unchanged; the width of line increased along with the pulse energy ascending when the process speed was fixed.
飞秒激光对薄膜进行微加工是一种用于制造微机电系统（MEMS）器件的新兴技术。使用钛宝石激光器（130飞秒，1000赫兹）以诸如脉冲能量等工艺参数的变化来辐照薄膜。薄膜厚度约为4微米，通过原子力显微镜（AFM）测量。当我们使用单脉冲激发薄膜时，烧蚀直径随着能量的增加而增大；当单脉冲能量不变时，改变脉冲数量时直径变化不大。在空气中这种超短脉冲长度下，金膜的单脉冲阈值通量为Fth = 0.7焦每平方厘米。通过改变激发脉冲的能量发现，当能量低于阈值时，薄膜上的线条隆起；当能量高于阈值时，线条呈凹形，这通过原子力显微镜检测到。还发现当脉冲能量不变时，线条宽度随着加工速度的增加而减小；当加工速度固定时，线条宽度随着脉冲能量的增加而增大。
