Temperature-dependent electrical characterization of high-voltage AlGaN/GaN-on-Si HEMTs with Schottky and ohmic drain contacts

Abstract In this work we present results of electrical parameters characterization of high-voltage AlGaN/GaN high electron mobility transistors with ohmic and Schottky drain electrodes on silicon substrates. The use of Schottky-drain contacts improves breakdown voltage ( V BR ), which was V BR  = 900 V for L GD  = 20 μm in contrast to V BR  = 505 V for ohmic-drain contacts. Both types of transistors exhibit drain current density of 500 mA/mm and leakage current of 10 μA/mm. Temperature-dependent characterization reveals a drain current density decrease with increasing temperature. The Schottky-drain HEMTs are characterized by lower increase of the R on (Δ R on  = 250% at 200 °C) in comparison to ohmic drain contacts (Δ R on  = 340% at 200 °C) relative to the room temperature due to decrease of on-set voltage of Schottky-drain HEMTs.