Research On Tip Wear In Nanoscale By Combined AFM And DIC Techniques

Recently, nanotechnology has been applied in many areas and become a hotresearch topic. Many countries have also focus on this technology for thedevelopment of their countries. However, the studies in nano-scale cannot beconducted directly instead of by means of more sophisticated equipment. Atomicforce microscopy (AFM) as a nano-scale high-resolution detection and processingtools, the applications is particular wide. AFM probe is the key components for itsdirect contact with the sample and the resolution of AFM mostly depends on thesharpness of a probe. However, during detecting, the wear of the probe is inevitable.So it is particularly important to study the wear of the probe. The tapping mode withhigher resolution has developed rapidly in recent years. And the most commonlyused probe in this mode is single-crystal silicon probes. So the experiments of thisstudy mainly focused on the wear of single-crystal silicon probe in the tapping-mode.In this thesis there are mainly three parts of research as following:First, the method combining the AFM and DIC is proposed to study the wear ofprobes and is verified theoretically. The geometric model and mathematicalsimulation model was established and ideal images only affected by the probe radiusare obtained. The results of DIC-radius curve proved that the AFM/DIC method isfeasible theoretically.Secondly, through experiment AFM/DIC method is proved feasible to evaluatethe wear of probe. Continuous scan experiments in situ are designed. Two kind ofDIC method is obtained to treat the images and the parameters of evaluating probewear is chose. Meanwhile, the DIC method is compared with other two commonmethods for tip evaluation and the advantages and disadvantages of each method arediscussed.Finally, single variable experimental is designed to study the impact of fourmain parameters in tapping mode: free amplitude, the amplitude setpoint, scanningspeed and probe radius. The influence reason of each parameter is analyzed and andthe characteristics of DIC method is summarized further.