Electrical characterization and DLTS analysis of a gold/n-type gallium nitride Schottky diode

This work describes a comparison of current density-voltage (J-V) and capacitance-voltage (C-V) properties measured as a function of temperature; deep trap properties are measured by deep level transient spectroscopy (DLTS) of Schottky diodes fabricated on n-type gallium nitride (GaN grown by metal organic vapor phase epitaxy (MOVPE). Unexpected behavior in the standard Richardson plot was observed in the temperature range 165-480 K, reflecting a range of Schottky barrier heights and a variation of ideality factor. This was explained by applying a Gaussian spatial distribution of barrier heights across the Schottky diode. C-V measurements were carried out in the temperature range 165-480 K to compare the temperature dependence of the barrier height with those obtained by the Gaussian distribution method. DLTS and high-resolution Laplace DLTS (LDLTS) show a majority carrier peak centered at 450 K.