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 (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. (author)