Nanoscale electromagnetic characterization of semiconductors and photovoltaics with scanning microwave microscopy

T.M. Wallis, A. Imtiaz, J. Weber, P. Kabos, M. Brubaker, N.A. Sanford, K.A. Bertness
National Institute of Standards and Technology, US

Keywords: scanning microwave microscopy, CIGS, metrology


Scanning probe microscopy enables electromagnetic characterization at the nanoscale, providing insight into local electronic density of states with sub-nanometer lateral resolution. Separately, tools based on the interaction of high-frequency signals with solid matter, such as time-resolved terahertz spectroscopy, provide powerful capabilities for non-contact measurements of drift mobility in GaN nanowires. The scanning microwave microscope (SMM) combines both capabilities of spatially-resolved characterization at the nanoscale and broadband sensitivity to carrier density and distribution. Applications of SMM to semiconductor systems include spatially-resolved measurements of complex impedance, absolute capacitance, sheet resistance, and carrier concentration.