Current-voltage characteristics of Cr/SiC(4H) Schottky diodes

Forward and reverse current-voltage characteristics (I–V ) of Cr/SiC(4H) Schottky diodes (SDs) manufactured using the same technology based on a single weakly-doped (~ 4·10¹⁴ cm^-3) epilayer are investigated. SDs are close to ideal, but a significant spread of I–V and excess current which sometimes unstable were found, unrelated to the difference in the area of the SDs. Investigation in the temperature range 20–210 °C revealed the annealing effect and allowed to estimate the potential barrier height of different diodes before and after annealing. It is suggested that the main diode is shunted by a parasitic diode, which determines forward I–V in the region of I–V exponential dependence.