Uniformity characterization of SiC, GaN, and α -Ga 2 O 3 Schottky contacts using scanning internal photoemission microscopy

Local variation within one dot electrode was characterized for Ni/SiC, Ni/GaN and Cu/Ti/ α -Ga 2 O 3 Schottky contacts by using scanning internal photoemission microscopy (SIPM). SIPM measurements were conducted for 200 μ m ϕ and 400 μ m ϕ dot electrodes with an energy resolution in determining Schottky barrier height ( qϕ B ) 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 qϕ B . 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.