Schottky Barrier Inhomogeneities of a 4H-SiC/Ni Contact in a Surface Barrier Detector

The surface barrier detector (SBD) is one of the solid state detectors used to measure charged particles and gamma-rays. To suppress the dark current in detector, the surface barrier height determines detector performance. The metal-semiconductor contact of SiC/Ni exhibits barrier inhomogeneity phenomena, I(V,T) and C(V), that depend on the temperature. The barrier height obtained from the I(V) data increased from 0.97 to 1.25 V with a increasing temperature, and the value obtained from C(V) data was 1.83 V. Gaussian potential model was used in order to explain the barrier height inhomogeneity observed in a 4H-SiC/Ni Schottky n-type diode detector. This discrepancy could be explained by local inhomogeneities at the Schottky contact by considering fluctuations in the local surface potential.