Annealing temperature influence on the degree of inhomogeneity of the Schottky barrier in Ti/4H–SiC contacts

Tung's model was used to analyze anomalies observed in Ti/SiC Schottky contacts. The degree of the inhomogeneous Schottky barrier after annealing at different temperatures is characterized by the 'T₀ anomaly' and the difference (ΔФ) between the uniformly high barrier height (Ф_B⁰) and the effective barrier height (Ф_B^eff). Those two parameters of Ti Schottky contacts on 4H–SiC were deduced from I–V measurements in the temperature range of 298 K–503 K. The increase in Schottky barrier (SB) height (Ф_B) and decrease in the ideality factor (n) with an increase measurement temperature indicate the presence of an inhomogeneous SB. The degree of inhomogeneity of the Schottky barrier depends on the annealing temperature, and it is at its lowest for 500-℃ thermal treatment. The degree of inhomogeneity of the SB could reveal effects of thermal treatments on Schottky contacts in other aspects.