Electrical characterization of deep levels created by bombarding nitrogen-doped 4HSiC with alpha-particle irradiation

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Authors

Omotoso, Ezekiel
Meyer, Walter Ernst
Auret, Francois Danie
Paradzah, Alexander Tapera
Legodi, Matshisa Johannes

Journal Title

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Volume Title

Publisher

Elsevier

Abstract

Deep-level transient spectroscopy (DLTS) and Laplace-DLTS were used to investigate the effect of alpha-particle irradiation on the electrical properties of nitrogen-doped 4H-SiC. The samples were bombarded with alpha-particles at room temperature (300 K) using an americium-241 (241Am) radionuclide source. DLTS revealed the presence of four deep levels in the as-grown samples, E0.09, E0.11, E0.16 and E0.65. After irradiation with a fluence of 4.1 × 1010 alpha-particles-cm–2, DLTS measurements indicated the presence of two new deep levels, E0.39 and E0.62 with energy level, EC – 0.39 eV and EC –0.62 eV, with an apparent capture cross sections of 2×10–16 and 2×10–14 cm2, respectively. Furthermore, irradiation with fluence of 8.9×1010 alpha-particles-cm–2 resulted in disappearance of shallow defects due to a lowering of the Fermi level. These defects - minutes. Defects, E0.39 and E0.42 with close emission rates were attributed to silicon or carbon vacancy and could only be separated by using high resolution Laplace-DLTS. The DLTS peaks at EC – (0.55-0.70) eV (known as Z1/Z2) were attributed to an isolated carbon vacancy (VC).

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Keywords

4H-SiC, Alpha-particle irradiation, Annealing, Schottky barrier diode, Deep-level transient spectroscopy (DLTS), Laplace-DLTS

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Citation

Omotoso, E, Meyer, WE, Auret, FD, Paradzah, AT & Legodi, MJ 2016, 'Electrical characterization of deep levels created by bombarding nitrogen-doped 4HSiC with alpha-particle irradiation', Nuclear Instruments and Methods in Physics Research Section B : Beam Interactions with Materials and Atoms, vol. 371, pp. 312-316.