Quantitative scanning microwave microscopy of 2D electron and hole gases in AlN/GaN heterostructures

Although the scanning microwave microscope (SMM) is based on atomic force (AFM), SMM differs from AFM by being able to sense subsurface electromagnetic properties of a sample. This makes promising for in-depth nondestructive characterization nanoelectronic structures. However, raw data are convoluted with sample topography, making it especially challenging quantitative nonplanar In this paper, using topography information simultaneously obtained and in situ extracted probe geometry, we de-embed topography-corrupted sheet resistance 2D electron or hole gas (2DEG 2DHG) buried at interface an AlN/GaN heterostructure, including lateral depletion 2DEG etched step. The results validated Hall-effect measurements. limitation possible improvement present technique discussed. With improved setup, can be used nondestructively monitor local 2DHG during device manufacture. These studies help pave way 3D tomography nanometer scale.