| Atomic force microscopy(AFM)is an important method to achieve micro-nano measurement and characterization,which is widely used in micro-nano manufacturing,science of materials,semiconductor,biomedicine and other fields.The development of miniaturization,three-dimensional(3D)structure and extreme performance of micronano devices has put forward higher requirements for the micro-nano fabrication and measurement technologies.3D multi-parametric surface characterization of micro-nano structures can analyze the coupling relationships between the surface topography,electrical and mechanical properties,providing necessary technical support for improving the manufacturing process of 3D micro-nano devices and optimizing their performances.However,the current AFM technology mainly focuses on the two-dimensional multiparametric surface characterization of micro-nano devices.How to realize 3D multiparametric surface characterization of micro-nano devices is a difficult problem to be solved in the current AFM research.In this dissertation,aiming at the multi-parametric surface characterization of 3D micro-nano devices,starting from the configuration design of the probe,an AFM system based on the orthogonal cantilever probe is constructed.The AFM characterization method for the surface topography,surface potential and surface nanomechanical properties mapping of 3D micro-nano structures is developed,to provide technical support for the research of 3D micro-nano devices structure and performance.An assembled probe with orthogonal cantilever structure is designed and fabricated,and an AFM system based on the orthogonal cantilever probe for 3D multi-parametric surface characterization is established.The structural parameters of the orthogonal cantilever probe are optimized by analyzing the static spring constants and the resonance frequency with simulation.A high-precision probe preparation method combining by the micro-machining with focused ion beam and micro-assembly with dual manipulators is developed.The calibration method for the static stiffness and dynamic natural frequency of the orthogonal cantilever probe is reported.In the AFM system for 3D multiparametric surface mapping,two kinds of driving devices,piezoelectric and magnetic drive,are constructed for bending and torsional excitation of the probe.Meanwhile,the specific scanning strategies of three working modes,bending,torsional and 3D scanning,are proposed.The 3D surface topography micro-nano mapping method is studied.To further improve the current characterization methods of 3D micro-nano surface topography,a 3D surface topography mapping technique combining the orthogonal cantilever probe and the probe vector angle tracking algorithm was proposed.In the AFM system set with a 360°rotation stage,the home positioning method and the amplitude compensation method are integrated.The orthogonal cantilever probe is used to realize omnidirectional spatial mapping for the surface topography of 3D structure with large depth steep sidewall and the3 D dense microarray units,and the quantitative analysis for the crucial dimensions of the3 D micro-nano structures is completed,to verify the stable,accurate and comprehensive detection ability of the proposed 3D surface topography micro-nano mapping technology.The 3D surface mechanical properties micro-nano mapping method is studied.Aiming at the lack of in-situ evaluation technique for the mechanical properties of 3D micronano surface,a method with the magnetic-drive orthogonal cantilever probe to realize 3D surface nanomechanical properties mapping is proposed.By establishing the interaction force models,the correlation between the effective indentation force and the sidewall angle is analyzed.To quantitatively evaluate the coupling relationship between 3D surface structure and 3D surface nanomechanical properties,combining the probe vector angle tracking and peak force tapping mode,the omnidirectional simultaneous spatial mapping of adhesion force,effective Young’s modulus,stiffness,energy dissipation,and topography on the 3D surface is executed with the orthogonal cantilever probe,which is regulated by the directionally magnetized particle in specific magnetic field.The 3D surface potential micro-nano mapping method is studied.Aiming at the lack of in-situ detection technique for 3D micro-nano surface potential,a method with the piezo-drive orthogonal cantilever probe to realize 3D surface potential mapping is proposed.A parallel plate capacitor model is used to analyze the weak cantilever homogenization effect during 3D surface potential characterization with the orthogonal cantilever probe.The superior linearity and energy resolution of the established 3D surface potential characterization system during measurement are illustrated by calibrating.To quantitatively evaluate the coupling relationship between 3D surface potential and topography,the high-resolution simultaneous spatial mapping of 3D surface potential and topography in situ and simulated working state of 3D micro-nano electronic devices is performed with the orthogonal cantilever probe,using the amplitude-modulated kelvin probe force microscopy.In summary,the research on micro-nano mapping technology for 3D surface multiparameters carried out in this dissertation can realize comprehensive quantitative evaluation of 3D surface topography,3D surface nanomechanical properties and 3D surface potential.It improves the current AFM methods for 3D surface properties detection,breaks through the space limitation in the surface mechanical and electrical properties measurement with traditional AFM,and provides technical support for the study of the coupling relationship of the multi-parameters on the 3D micro-nano devices surface.The relevant research results will effectively promote the development of 3D micro-nano structures,and have important scientific values and application prospects in the innovation of biosensors,micro-electro-mechanical systems,semiconductor chips and other fields. |
