EFFECT OF ROOM TEMPERATURE ANNEALING ON Ni/4H-SILICON CARBIDE SCHOTTKY CONTACTS AFTER ALPHA-PARTICLE IRRADIATION AT HIGH FLUENCE
The aim of this work is to study the effect of room temperature annealing on defects emanated after bombarding 4H-SiC Schottky contacts with 5.4 MeV alpha-particles at a fluence of 9.2 × 1011 particles-cm–2. The investigation was carried out by means of current-voltage and capacitance-voltage measuring techniques carried out at room temperature (300 K), and deep level transient spectroscopy measured at temperature range 25 – 350 K. The dependence of ideality factor, Schottky barrier height and net doping concentration of the devices were explored after irradiation and room temperature annealing. The ideality factor increases after irradiation and subsequently decreases after room temperature annealing but vice-versa for Schottky barrier height and free carrier concentration. The activation energies of the new defects introduced after irradiation were determined to be 0.39 and 0.62 eV, and their corresponding apparent capture cross section were calculated to be 1.7 × 10–15 and 1.0 × 10–13 cm2. It was observed that the deep level defect with the activation energy of 0.39 eV annealed out at room temperature after one week.