Electrical properties of photoanodically generated thin oxide films on n-GaN

The characteristics of photoelectrochemically (PEC) generated gallium oxide films on n-GaN using an 0.002 M KOH electrolyte are described. The chemica l composition of the resistive layers was analyzed by Auger electron spectr oscopy. The DC and HF characteristics of Al/Ti/PEC-Ga2O3 (gallium sesquioxi de)/GaN structures were studied with current-voltage and capacitance-voltag e measurements, respectively. Under reverse bias we found extremely low lea kage currents (< 10(-8) Acm(-2) at -15 V) and a very low interface state de nsity: high-temperature operation (up to 166 degreesC tested) motivates the integration of the described dielectric layer forming technique into GaN b ased device process schemes. Our method may also be employed as gate recess technology. (C) 2001 Elsevier Science B.V. All rights reserved.