金刚石表面飞秒激光直写微米石墨线

Study of Graphite Line Micromachining on Diamond Surface by Femtosecond Laser Direct Writing

利用120 fs、800 nm钛蓝宝石飞秒激光器微纳加工系统,在化学气相沉积金刚石薄片表面进行了石墨化的研究,得到了导电性良好的微米尺度的石墨线。利用Raman光谱研究了激光的功率、激光扫描速度等对石墨化程度的影响规律。结果表明,在飞秒激光直写区域有纳米晶石墨、无定型碳及残留金刚石存在。优化辐照激光能量和激光扫描速度参数,可以得到较好的纳米晶石墨线结构。以10μm/s扫描速度,1.14μJ激光能量刻写出了毫米级长度的石墨线。利用半导体电阻测试仪对其伏安特性进行了测试,测得1 mm长石墨线的电阻约67.2 kΩ。该研究对基于金刚石的生物传感器、放射量测定计,及器件内掩埋石墨电极等制备都有一定的指导意义。

The fabrication of graphitic lines induced on the surface of single-crystal diamond plates by using of 120 fs laser pulses at 800 nm wavelength was reported. The diamond plates were man-made diamond by chemical vapor deposition. Different parameters of laser fluence and graphitization speed were used for fs laser direct writing. A Raman investigation was performed to study the graphitic structural properties. The Raman peak features indicated that there were nanocrystalline graphite,amorphous carbon,and a residual diamond content in the laser modified zone. Optimized laser fluence and scan speed led to a better graphitic material in terms of degree of crystallinity. Furthermore,the conductivity of graphite lines were investigated by a semiconductor parameter analyzer. A graphitic line with 67. 2 kΩper millimeter was gained,and was micromachined by fs laser direct written under laser fluence of 1. 14 μJ and a scan speed of 10 μm / s. This study is helpful to the application of diamond-based devices with graphite electrodes,biosensors,and radiation detectors,etc.