We investigated the effects of recovery schemes on the characteristics of GaN Schottky diodes damaged by inductively coupled
Cl2/H2/normalAr/CH4
plasma etching. The recovery schemes included
N2
plasma exposure,
N2
plasma plus annealing at 600°C in
N2,
and annealing at 700°C in
N2.
Ga-deficient GaN surface layers were observed after etching the GaN, and the Ga/N stoichiometry at the surface was most strongly affected by the
Cl2
flow rate among the process variables. The samples annealed at 700°C showed a clear improvement in diode characteristics and a complete restoration of the Ga/N ratio from ca. 0.87 to ca. 1.0 at the surface layers, as measured by Auger electron spectroscopy. For all other damage-recovery schemes, the samples showed no significant enhancement in diode characteristics and incomplete restoration of Ga/N stoichiometry at the surface layers. © 2001 The Electrochemical Society. All rights reserved.