Effect of Proton and Electron Irradiation on Current-Voltage Characteristics of Rectifying Diodes Based on 4H-SiC Structures with Schottky Barrier

Abstract:

Forward and reverse current-voltage (I-V) characteristics of commercial rectifying Schottky diodes (SDs) based on silicon carbide (4H-SiC, base layer doping level 3·10¹⁵ cm^-3) have been studied under irradiation with 0.9 MeV electrons and 15 MeV protons. The starting diodes were characterized by a barrier height of ~1.5 eV and nearly ideal forward and reverse I-V characteristics. It was found that, at doses exceeding the threshold dose D_th, the series differential resistance R_s of the diodes grows as R_s ~ D^m (m = 10-15) and shows no tendency toward saturation. D_th ≈7·10¹⁵ cm^-2 under electron irradiation, and D_th ≈ 4·10¹³ cm^-2 in the case of irradiation with protons. Heating to 200oC results in that R_s decreases with activation energy of ~1.1 eV and R_s is partly annealed-out with activation energy of ~0.7 eV. The starting Schottky diodes changes only slightly under irradiation, but, possibly, the irradiation leads to an over-compensation of the n-type layer and formation of an additional barrier in the form of a pn junction.

• Periodical: Materials Science Forum (Volume 1004)
• Pages: 1081-1087
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1004.1081
• Online since: July 2020
• Authors: Anatoly M. Strel'chuk*, Vitalii V. Kozlovski, Alexander A. Lebedev
• Keywords: Electron Irradiation, Overcompensation, Proton Irradiation, Radiation Hardness, Rectifying Diode, Series Resistance, Silicon Carbide, Threshold Dose

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