Analysis of the reverse leakage current in AlGaN/GaN Schottky barrier diodes treated with fluorine plasma

The carrier transport mechanism of CF4 plasma-treated AlGaN/GaN Schottky barrier diodes (SBDs) under reverse bias is investigated. The reverse leakage current is reduced by similar to 2 orders of magnitude after the CF4 plasma treatment, but increases exponentially with increasing temperature, indicating that a thermally activated transport mechanism is involved. Based on the activation energy estimated from temperature-dependent current-voltage characteristics and the emission barrier height extracted from Frenkel-Poole emission model, it is suggested that the dominant carrier transport mechanism in the CF4 plasma treated SBDs is the Frenkel-Poole emission from fluorine-related deep-level states into the continuum states of dislocations. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.3697684]