Microwave imaging at the nanoscale: quantitative measurements for semiconductor devices, materials science and bio-applications

Abstract

This article will examine a novel high frequency electrical characterization microscope for the nano-scale imaging of semiconductor devices, advanced materials and biological samples. The scanning microwave microscope (SMM) can extract quantitative material properties at Giga-Hertz (GHz) frequencies with nanometre accuracy. The SMM interfaces two well-known measurement tools, the atomic force microscope (AFM) for materials characterisation and the vector network analyser (VNA) from telecommunication network testing for reliable microwave signal measurements. The AFM allows for nanometre lateral resolution imaging, and the VNA provides high precision impedance and admittance measurements at broadband frequencies from MHz to GHz. We give a review of this microscope including nanoscale imaging of semiconductor devices and failure analysis, as well as calibrated impedance imaging of advanced materials. Finally, we show the first calibrated complex impedance image of bacteria at 20 GHz, as well as a microwave image of a living endothelial cell acquired in liquid buffer media. This new microscope combines advanced nanotechnology imaging with microwave electronics and 3D sample modeling, for the study of advanced materials and for the first time also to bio-molecules and cells in living condition.