Structural Optimization And Processing Research Of Quartz Tuning Fork For Atomic Force Microscope

In recent years,with the development of atomic force microscope(AFM)technology,the force sensor of the microscope probe part has become more and more demanding.However,the traditional silicon cantilever force sensor in the AFM has low quality factor,poor stability,complicated detection device,detection range Limitations and other shortcomings,which can no longer meet AFM's further pursuit of high accuracy and high stability.At the same time,some researchers reported the use of quartz tuning forks as force sensors for AFM probes,which achieve high quality factors,good stability,self-excitation and self-detection,and wide detection range Therefore,it is an ideal choice to use quartz tuning fork as the force sensor of AFM probe.However,so far most of the tuning forks used in the AFM research based on quartz tuning forks come from the tuning fork crystals already on the market,which limits the frequency and size selection of tuning forks,and the batch processing technology of small size quartz tuning forks is not yet mature.It makes it difficult to customize the production of various quartz tuning forks that meet AFM requirements.Therefore,this thesis aims at the above problems,first obtains the optimized structure of the quartz tuning fork through finite element simulation,and then fabricated the optimized quartz tuning fork.The specific research is as follows:1.Through the ANSYS finite element modal simulation analysis of the commercially available quartz tuning fork,the simulation results meet the actual needs,and then a series of laws for tuning fork finite element simulation are obtained.Through the rules,the size of the quartz tuning fork is adjusted to obtain the quartz tuning fork size and the corresponding operating frequency that meet the requirements of AFM.Then a part of the structure of the tuning fork is optimized and changed to determine the size of the tuning fork after the structure is changed,and the electrodes are set on the surface of the tuning fork.Finally,Auto CAD is used to draw the layout of the substrate with various styles and sizes of tuning forks,which are used as subsequent lithography mask layouts.2.We selected the Z-tangent quartz substrate as the processing material,through experimental exploration of the quartz tuning fork processing technology,determine a set of basic process flow,and fabricated the quartz tuning fork resonator according to the process flow;In the process of processing,the main research is on the plating of the mask layer,the photolithography process,the quartz wet etching process and the production of the surface electrode,especially the research,design and conduct of the quartz wet etching process Multiple sets of exploratory experiments were used to optimize various experimental parameters,and finally a quartz tuning fork with relatively flat side walls and relatively intact surface electrodes was obtained.