DEVELOPMENT OF NANO-SCALE CHARACTERIZATIN TECHNIQUES BY AUGER ELECTRON SPECTROSCOPY

随着纳米结构材料的广泛应用,新型微纳尺度表征技术成为纳米科学技术发展的重要途径。本文基于局域电子信息全面性的思想,从俄歇电子能谱的原理出发,理论推导出俄歇价电子能谱的简明表述方式,确定俄歇价电子能谱与微观电子结构信息的内在联系和物理意义,建立了俄歇电子能谱探测微区一系列宏观参量的新技术。其中应力测量技术的空间分辨率可优于20nm,为微纳尺度力学测量的发展提供了重要的方法;非接触性的局域电学性质测量技术,超越了传统电学测量方法的思想框架,实现了无外场驱动的电荷密度分布、电场分布等本征电学性质表征、以及半导体异质结构整个空间区域的能带构造;结构相的测定技术,使纳米微区材料的晶体结构相识别成为可能;半导体微区导电类型测定技术,延续了非接触性电学测量的优点,并且能够灵活地探测分析复杂光电器件结构中不同区域的导电类型分布。通过实际应用于侧向外延GaN不同区域、AlxGa1-xN/GaN超晶格量子阱结构、ZnO纳米颗粒等纳米尺度复杂体系的微区宏观性质探测,获得应力/应变、电荷密度/电场、结构相以及导电类型及其分布等结果,验证了所建立的测量技术的有效性和可靠性。Inspired by the rapid progresses and wide applications of nanostructured materials,novel nano-scale characterization techniques have attract much attention in nanoscience.Based on the concept of full information of local electron,we initiate with the principle of Auger electron spectrum,simplify the theoretical expression spectrum,reveal the intrinsic relationship between the valence-band Auger electron spectrum and the microscopic electronic structures,and develop a couple of novel nano-scale detection techniques for several important physical parameters.1) A technique for local strain measurement is achieved with a spatial resolution better 20nm,which provides an effective method for the investigations of mechanical properties in nano-scale;2) A non-contact probing of local charge and electric field exempts from the influence of external field and enables construction of energy band for semiconductor heterostructures,which is beyond the conventional frame of electrical measurement;3) A technique for structural phase identification is developed to distinguish local structures in nano-structural materials;4) A technique for determination of conductivity type in semiconductor is able to apply to the local type detection in complex structures of optoelectronic devices.Practical applications of these novel techniques have been carried out on nano and complex structures,such as epitaxial-lateral-overgrowth GaN,AlxGa1-xN/GaN superlattice,ZnO nanoparticle,and so on.A series of precise results and interesting phenomena about strain,charge concentration,electric field,structural phase,conductivity type,and their distributions have been obtained in these structures,which provided an objective evaluation for the solidity and effectiveness of these techniques