超快激光制备铌酸锂基金属叉指电极工艺研究

Study on Fabrication of Metal Interdigital Electrodes on LiNbO3 Substrate by Ultrafast Laser

利用波长1064 nm、脉冲宽度10 ps、重复频率100 kHz的超快脉冲激光,刻蚀了铌酸锂基底上的银铬双层薄膜,研究了激光能量密度和扫描速度对银铬双层薄膜表面刻蚀沟槽质量的影响以提高沟槽质量。结果表明,激光能量密度5.38 J/cm~2、扫描速度500 mm/s是激光刻蚀沟槽的最佳激光参数,沟槽底部基底完整无损,沟槽边缘没有明显裂纹,保证最终刻蚀获得的叉指电极具有优良性能,同时相应的沟槽宽度约为14μm,使得加工线宽14μm及以上的高质量叉指电极成为可能,能够满足生物医学领域声表面波器件对叉指电极的需求。设计并以优化参数加工了一对应用于生物医学领域声表面波器件的叉指电极,其加工精度较高,表面形貌良好,电极间无粘连等缺陷。

The Ag–Cr film on the LiNbO3substrate was etched by an ultrafast pulsed laser with a wavelength of 1064 nm,a pulse width of 10 ps,and a repeat frequency of 100 kHz.The effects of laser energy density and scanning speed on the quality of etched grooves on Ag–Cr films were studied to improve the groove quality.The results show that the laser energy density of 5.38 J/cm~2 and the scanning speed of 500 mm/s are the optimal laser parameters for etching grooves.In this case,the substrate at the bottom of the trench is intact,and there is no obvious crack at the edge of the trench,which ensures that the final etched interdigital electrode has excellent performance.At the same time,the corresponding groove width is about 14μm,which makes it possible to process high-quality interdigital electrodes with a line width of 14μm and above,which can meet the needs of interdigital electrodes for surface acoustic wave devices in the biomedical field.A pair of interdigital electrodes for surface acoustic wave devices in the biomedical field were designed and fabricated with optimized parameters.They have high machining accuracy,good surface morphology and no defects such as adhesion between electrodes.