Electrical characterization of electron irradiated and annealed lowly-doped 4H-SiC

Irradiation effect of primary knock-on atoms on conductivity compensation in N-type 4H-SiC Schottky diode under various irradiations

“…The nitrogen doped epilayer 4H-SiC samples with a doping density of 5×10 16 cm −3 were used in this study. The back side of the sample had a high doping density of 1×10 19 cm −3 for the fabrication of ohmic contacts. The wafer was cut into the size of 2 mm×2 mm.…”

“…Other conductive mechanisms, such as the generation-recombination mechanism, could also play an important role [16]. The increase of the ideality factor due to irradiation could be attributed to the formation of defects close to the semiconductor/metal interface [18], which acts as recombination centres during the conduction process, leading to the increasing of the recombination current and the ideality factor [11,16,19]. For Schottky diodes, the Schottky barrier height is related to the density of interface traps [19].…”

“…Fluence 16 1.75 1.92 1×10 14 1.02 1.00 4.81 100 3.27×10 16 1.79 1.96 1×10 15 1.02 1.00 4.83 101 3.25×10 16 1.9 2.07 2×10 16 1.03 interface traps produced by irradiation were also an important reason for the barrier height reduction. The increasement in series resistance indicates that the reason could be the decreasing of the mobility and the free carrier concentration, or the compensation of doping in the semiconductor [17][18][19].…”

“…From the experiment results, the reverse leakage current decreased with the increasing radiation fluence of Si and C ions, while while it nearly stayed constant before and after electron irradiation, due to the lack of deep level traps. It would be also related to the collective effect of the defect centres and the decrease in free carrier density induced by particles [19].…”