Effect of N₂O/BCl₃ cyclical recess etching technique used prior to anode metal deposition in AlGaN/GaN Schottky barrier diodes

This paper presents AlGaN/GaN Schottky barrier diodes (SBDs) with plasma treatment and recessed anodes for use in high-power and high-temperature electronics applications. Four structures with/without various cycles of plasma treatment were investigated to reduce turn-on voltage (VON) and improve reverse recovery characteristics. The SBDs fabricated with plasma treatments realized higher specific on-resistance (R_{ON_SP}) and lower V_ON than the device without plasma treatment. The optimal device was the SBD fabricated with 2^nd cycles of plasma treatments, which had R_ON of 8.57 m-cm², V_ON of 0.83 V, and breakdown voltage of 917 V. In addition, a slight decrease in diode current dispersion during stress measurement was obtained for the SBD fabricated with 2^nd cycles of plasma treatments because the increase in the number of plasma treatment cycles resulted in the formation of more traps on the anode contact.