Electrical characterization of 5.4 MeV alpha-particle irradiated 4H-SiC with low doping density

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Authors

Paradzah, Alexander Tapera
Auret, Francois Danie
Legodi, Matshisa Johannes
Omotoso, Ezekiel
Diale, M. (Mmantsae Moche)

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Elsevier

Abstract

Nickel Schottky diodes were fabricated on 4H-SiC. The diodes had excellent current rectification with about ten orders of magnitude between 50 V and +2 V. The ideality factor was obtained as 1.05 which signifies the dominance of the thermionic emission process in charge transport across the barrier. Deep level transient spectroscopy revealed the presence of four deep level defects in the 30–350 K temperature range. The diodes were then irradiated with 5.4 MeV alpha particles up to fluence of 2.6 1010 cm 2. Current–voltage and capacitance–voltage measurements revealed degraded diode characteristics after irradiation. DLTS revealed the presence of three more energy levels with activation enthalpies of 0.42 eV, 0.62 eV and 0.76 eV below the conduction band. These levels were however only realized after annealing the irradiated sample at 200 C and they annealed out at 400 C. The defect depth concentration was determined for some of the observed defects.

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Keywords

n-Type 4H-SiC, Schottky diode, Deep level transient spectroscopy (DLTS), Alpha particle irradiation, Defects

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Citation

Paradzah, AT, Auret, FD, Legodi, MJ, Omotoso, E & Diale, M 2015, 'Electrical characterization of 5.4 MeV alpha-particle irradiated 4H-SiC with low doping density', Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms, vol. 358, pp. 112-116.