Development Of Scanning Head Based On Qplus Sensor Of Scanning Probe Microscopy

The first scanning tunneling microscopy was invented in1981by Binning andRohrer，and then the family of scanning probe microscopy has been rapidly developedand widely applied in surface science, life science, micro/nano-fabrication andprecision measurement of weak force. Particularly, the atomic force microscope canimage insulating surfaces as well as conducting surface. In addition, atomic forcemicroscope can also be used for precision measurement of weak force. In thisdissertation, I describe the design and build of a scanning probe microscope whichwill be used for Casimir force precision measurement.The scanning probe microscope can work in both scanning tunneling microscopyand atomic force microscopy mode. This dissertation focuses on the atomic forcemicroscope scanning head based on Qplus sensor. First, the design of scanning headis described in order to show how to design a rigid, stable and multifunctionalscanning head. Secondly, the development of a preamplifier used at low temperaturein ultrahigh vacuum is introduced. Multisim, a software of circuit design andsimulation, was used for the design and simulation of this preamplifier. Thepreamplifier was then built and tested both at room temperature and liquid nitrogentemperature. Last, the performance of scanning probe microscope was tested byimaging on HOPG both in STM and AFM mode. Atomic resolution was achieved inSTM mode and only atomic step was resolved in the AFM mode. Based on the STMimages on HOPG, the scanner tube was calibrated.