Effect of high energy electron irradiation on low frequency noise in 4H-SiC Schottky diodes

The low-frequency noise in high voltage Ni/4H-SiC Schottky diodes irradiated with high energy (0.9 MeV) electrons was studied in the frequency range from 1 Hz to 50 kHz, temperature interval 295–410 K, and irradiation dose Φ from 0.2 × 1016 cm−2 to 7 × 1016 cm−2. The noise amplitude was found monotonically increasing with the irradiation dose. With the irradiation dose increase, the noise spectra on the linear part of the current voltage characteristic transform from the 1/f noise to the generation recombination noise of at least two trap levels. One of these levels can be classified as Z1/2 with the capture cross section determined from the noise measurements to be ∼10−15 cm2.