Suppression of current leakage along mesa surfaces in GaN-based p-i-n diodes

Abstract

Trifluoromethane-containing plasma is used to passivate the mesa surfaces and suppresses the surface leakage current of GaN p-i-n rectifiers. Reduction of surface leakage enhances the reverse blocking voltage by 25% measured at $J=1$ A/cm 2. Differential forward resistances of control samples and plasma-treated ones are 0.65 and 0.49 mΩ-cm 2, respectively, and an excellent Baliga's figure-of-merit of more than 800 MW/cm 2, as compared with the conventional 545 MW/cm 2, is achieved for GaN diodes fabricated on sapphire substrates.