电压对原子力显微镜探针振动的影响

Effects of the voltage on vibration of the atomic force microscope probe

在原子力显微镜(atomic force microscope,AFM)的轻敲模式中,针尖-样品相互作用力对探针振动产生干扰,降低测量精度。为探究电压对针尖-样品作用力的影响,通过实验测定不同电压下探针匀速远离硅片表面时的悬臂受力、振幅及相位随探针位移的变化,并利用玻璃和银样品重复同样的实验步骤以探究样品导电性对实验结果的影响。结果表明,探针所带电压增大使得探针受到的静电力增大,导致针尖-样品相互作用力和能量耗散增大,阻碍了探针振动。研究揭示了电压与样品导电性对针尖-样品相互作用力的影响规律与影响机制。

In the tapping mode of atomic force microscope(AFM),the tip-sample interaction interfaces with probe vibration,which reduces the measurement accuracy.In this work,variations of the force,amplitude and phase with the vertical displacement upon AFM probe with different voltages leaving a silicon sample were simultaneously collected,which was aimed to investigate the effects of the voltage on the tip-sample interaction.Besides,the same experiments were conducted by using a glass and a silver sample to study the influence of sample conductivity on the experimental results.It’s noted that the increase of probe voltage caused the increase of the electrostatic force,leading the increase of tip-sample interaction and energy dissipation,and finally hindered the probe vibration.The laws and mechanism of the voltage and sample conductivity affecting the tip-sample interaction were revealed in the study.