Abstract:
Current–voltage, capacitance–voltage and conventional deep level transient spectroscopy at temperature
ranges from 40 to 300 K have been employed to study the influence of alpha-particle irradiation from an
241Am source on Ni/4H–SiC Schottky contacts. The nickel Schottky barrier diodes were resistively evaporated
on n-type 4H–SiC samples of doping density of 7.1 1015 cm 3. It was observed that radiation
damage caused an increase in ideality factors of the samples from 1.04 to 1.07, an increase in Schottky
barrier height from 1.25 to 1.31 eV, an increase in series resistance from 48 to 270 X but a decrease in
saturation current density from 55 to 9 10 12Am 2 from I–V plots at 300 K. The free carrier concentration
of the sample decreased slightly after irradiation. Conventional DLTS showed peaks due to four deep
levels for as-grown and five deep levels after irradiation. The Richardson constant, as determined from a
modified Richardson plot assuming a Gaussian distribution of barrier heights for the as-grown and irradiated
samples were 133 and 151 A cm 2 K 2, respectively. These values are similar to literature values.
