Uniformity characterization of SiC, GaN, and α-Ga2O3 Schottky contacts using scanning internal photoemission microscopy

Local variation within one dot electrode was characterized for Ni/SiC, Ni/GaN and Cu/Ti/α-Ga2O3 Schottky contacts by using scanning internal photoemission microscopy (SIPM). SIPM measurements were conducted for 200-μmΦ and 400-μmΦ dot electrodes with an energy resolution in determining Schottky barrier height (qΦB) of less than 0.2 meV. All three kinds of Schottky contacts on the wide bandgap semiconductors exhibited good uniformity as small as less than 10 meV in a standard deviation of qΦB. The Schottky barrier height and the standard deviation values are the basis for estimating device performances and designing large-area devices as a measurement-based physical value.