Abstract The Ni/4H-SiC Schottky barrier diodes (SBDs) and transfer length method (TLM) test patterns of Ni/4H-SiC Ohmic contacts were fabricated, and irradiated with 1 MeV electrons up to a dose of 3.43×1014 e/cm-2. After radiation, the forward currents of the SBDs at 2 V decreased by about 50%, and the reverse currents at -200 V increased by less than 30%. Schottky barrier height ($\phi_{\rm B}$) of the Ni/4H-SiC SBD increased from 1.20 eV to 1.21 eV under 0 V irradiation bias, and decreased from 1.25 eV to 1.19 eV under -30 V irradiation bias. The degradation of $\phi_{\rm B}$ could be explained by the variation of interface states of Schottky contacts. The on-state resistance (Rs) and the reverse current increased with the dose, which can be ascribed to the radiation defects in bulk material. The specific contact resistance ($\rho_{\rm c}$) of the Ni/SiC Ohmic contact increased from 5.11× 105 $\Omega\cdot$cm2 to 2.97×10-4 $\Omega\cdot$cm2.
Received: 08 December 2008
Revised: 19 March 2009
Accepted manuscript online:
Fund: Project~supported~by~the National
Natural Science Foundation of China (Grant No 60606022), the Xian
Applied Materials Foundation (Grant No XA-AM-200702) and the
Advanced Research Foundation (Grant No 9140A08050508).
Cite this article:
Zhang Lin(张林), Zhang Yi-Men(张义门), Zhang Yu-Ming(张玉明), Han Chao(韩超), and Ma Yong-Ji(马永吉) High energy electron radiation effect on Ni/4H-SiC SBD and Ohmic contact 2009 Chin. Phys. B 18 3490
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