Comparative Results of Low Temperature Annealing of Lightly Doped n-Layers of Silicon Carbide Irradiated by Protons and Electrons

摘要

The influence of low-temperature (up to 400°C) annealing on the current-voltage and capacitance-voltage characteristics of Schottky diodes irradiated with protons with an energy of 15 MeV compared with the results of annealing of structures after irradiation with electrons with an energy of 0.9 MeV has been studied. It has been shown that in case of proton irradiation with a dose of 4×10~(13) cm~(-2) and electron irradiation with a dose of 1×10~(16) cm~(-2), only partial carrier compensation occurs and the differential resistance is completely determined by the number of carriers in the epitaxial layer. The irradiation method has almost no effect on the direct current dependence on the voltage in the exponential segment. The ideality coefficient remains almost unchanged within 1.03 ÷ 1.04. During annealing after proton irradiation, a large activation energy of the process is required. The temperature of the beginning of annealing process during proton irradiation shifts to a larger value, from 150 °C to 250 °C when compared with electron irradiation. It has been demonstrated that at low doses of proton irradiation, the low-temperature annealing leads to the return to the conduction band of up to 65% of the removed charge carriers. After electron irradiation, low-temperature annealing returns up to 90% of the removed charge carriers to the conduction band. This indicates that at room temperature both proton irradiation as well as electron irradiation introduce both stable and unstable defects but in different proportions.