Vertical GaN Schottky barrier diodes with ohmic contact on N-polar by the atomic layer deposition of aluminum oxide interfacial layer

In this paper, high-performance vertical GaN on GaN Schottky Barrier Diodes (SBDs) on 2-inch free-standing (FS)-GaN is presented with the specific on-state resistance (R-on) of 1.34 m Omega<middle dot>cm(2), breakdown voltage (V-br) of 1150 V and figure of merit (FOM) of 0.98 GW/cm(2). He-implanted edge termination (ET) structure is introduced to alleviate the peak electric field concentration effect at the anode edge of GaN SBDs. Furthermore, A new ohmic contact structure is explored by atomic layer deposition (ALD)-grown AlOx interfacial layer. Based on the self-cleaning effect of ALD and Ultra-thin AlOx interfacial layer, the Fermi-level Pinning (FLP) effect is alleviated effectively, the specific contact resistivity (rho(c)) on N-polar GaN was reduced from 1.63 x 10(-3) to 7.14 x 10(-5) Omega<middle dot>cm(2).The temperature variation test demonstrate the devices has potential of temperature sensors under high voltage and high temperature.