Ho Won Jang, Jong Kyu Kim, Chang Min Jeon, Jong-Lam Lee
Pohang University of Science and Technology
cm2 ,
realized without annealing. Using synchrotron radiation photoemission
spectroscopy, it was observed that the Fermi level moved by 0.5 eV toward the
conduction band edge and the atomic ratio of Ga/N was increased by the
treatment. This suggests that a number of N vacancies were produced at the
treated surface and the Fermi level was pinned at the energy level of N
vacancies near the conduction band. The N vacancies acting as donors for
electrons produced a number of electrons, resulting in the near surface region
to be in the degenerate state. Both the shift of Fermi level and the production
of electrons at the treated surface lead to the reduction in contact
resistivity through the decrease of the effective Schottky barrier for
conduction of electrons. © 2001 The Materials Research Society