Development of apertureless microscopy and force microscopy of gallium nitride and cerium oxide

This thesis concentrates on the development of both novel scanning probes as well as novel applications of existing ones in three major areas. The first area is our development of apertureless microscopy and progress toward our goal of 1nm optical imaging and spectroscopy. Fundamental experiments and simulations of the apertureless imaging mechanism were conducted using nanosphere size standards. Fifteen nanometer resolution as well as optical property discrimination was demonstrated. The apertureless microscope was then used to investigate the near field optical structure of chromosomes and anti-reflective polymer thin films. The second area is the investigation of the electronic properties of the wide bandgap semiconductor GaN by atomic force microscopy. Defects in GaN were correlated to diffusion lengths as measured by electron beam induced current. Electric force microscopy (EFM), a varient of atomic force microscopy, was subsequently used to investigate sub 1 m m electric field gradient and surface potential variation associated with these defects. A novel application of EFM to measure the surface state density was also demonstrated. The third area is another novel application of EFM for localized charge storage in double barrier CeO2/Si/CeO2/Si structures which may have relevance for data storage and charge directed lithography.