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 (φ 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 φ 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 (\rhoc) of the Ni/SiC Ohmic
contact increased from 5.11× 105~Ωega.cm2 to 2.97× 10-4~Ωega.cm2.
Received: 08 December 2008
Revised: 19 March 2009
Published: 20 August 2009
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, Zhang Yi-Men, Zhang Yu-Ming, Han Chao, Ma Yong-Ji High energy electron radiation effect on Ni/4H-SiC SBD and Ohmic contact 2009 Chin. Phys. B 18 03490