Research On Imaging Based On Scanning Near-Field Microwave Microscopy System

The imaging technology of the microcosm is the most direct and effective method to study the structure and properties of materials.The innovative development of imaging technology is closely related to the development of physics,chemistry,biotechnology and other fields.In recent years,with the rapid development of integrated circuits and nanoscience and technology,it is necessary to invent more advanced detection instruments to detect the important properties of the film formation quality and electromagnetic parameter distribution of microstructure materials.In addition,in the field of basic biology research,high-resolution biological imaging methods must be used to obtain information about the dynamic changes of biological systems in order to accurately understand the internal mechanisms of organisms.Compared with far-field microscopy,near-field microscopy breaks through the Abbe diffraction limit,and can resolve materials below one wavelength size,so its resolution is greatly improved.Microwaves are penetrating and can detect the surface of objects and deeper information.With the research breakthrough and development of the near-field scanning microwave microscope system,its imaging applications in the field of semiconductor integration technology and life sciences have been recognized.However,the imaging strategy of this system brings some shortcomings.The biggest problem is that the weak and unresolvable tilt of the sample stage or the sample itself causes tilt errors to the global scanning parameters,which causes the image to be distorted by a certain angle of horizontal tilt.In addition,the mechanical noise of the system device causes the noise of the signal,resulting in noise in the image.Therefore,with the development of scanning near-field microwave microscopes to the field of higher resolution,some correction methods are urgently needed to solve the problem of imaging distortion.In this thesis,based on the research of the near-field scanning microwave microscope system,its imaging algorithm and imaging analysis are done.The system obtains the imaging image by detecting the deviation of the resonance frequency,S-parameter and quality factor of the resonant cavity,and using the difference of the deviation.Through the theoretical analysis of near-field microwave,HFSS simulation is used to analyze the two-port quarter-wavelength coaxial resonator,and several factors affecting its performance are analyzed.Based on the problem that the sample tilt of the probe scanning imaging system causes the image quality to deteriorate,the surface scan image tilt correction algorithm,the line scan curve tilt correction algorithm and the image smoothing denoising correction algorithm are researched,and the algorithm is implemented through MATLAB code.Based on the system’s integrated imaging correction software,a development design is made,then the imaging of the copper thin film network verifies the practicability and effectiveness of the algorithm.On the basis of online scanning test,the method of measuring half-height width is used to compare the detection sensitivity of several probe conditions and verify the simulation experiment.Finally,using the near-field scanning microwave microscope system,the metal texture,lithography palindrome,lithography aperture,lithography letters and other metal microstructure samples are analyzed by line scan and area scan,and the methods proposed in this thesis are used to modify image,greatly improving its imaging quality.On biological samples,the use of microwave penetration through the gradual positioning and refinement of the leaf first,second,third,and fourth-level vein structure distribution imaging analysis of the study,the use of correction methods to improve its imaging Quality,development system potential in the field of biological testing.