In this study, we will report the effect of dry etching conditions on etching rates and damage induced by the ion bombardment on vertical β-Ga2O3 rectifiers. A Plasma Therm 760 Inductively Coupled Plasma (ICP) system was employed for dry etching by varying the ICP power ranging from 100 to 800W, chuck power (15-400 W) with either Cl2/Ar or BCl3/Ar discharges. The highest etch rate achieved was ~130 nm/min using 800 W ICP source power and 200 W chuck power (13.56 MHz). The etched Ga2O3 surfaces become oxygen-deficient under strong ion-bombardment conditions, and the electrically active damage introduced during etching was quantified using Schottky barrier height and diode ideality factor measurements. For low etch rate conditions (~12 nm/min) at low powers (150 W ICP source power at 2 MHz and 15 W rf chuck power at 13.56 MHz). There was only a small decrease in reverse breakdown voltage (~6%) while the Schottky barrier height decreased from 1.2 eV to 1.01 eV and the ideality factor increased from 1.00 to 1.06. Under higher etch rate (~70 nm/min) and power (400 W ICP and 200 W rf power) conditions, the damage was more significant, with the reverse breakdown voltage decreasing by ~35%, the barrier height was reduced to 0.86 eV and the ideality factor increased to 1.2. By annealing the etched samples at 450°C, the Schottky barrier height, diode ideality factor and reverse breakdown voltage were restored as compared to the reference sample.
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