Ultra-low turn-on voltage (0.37 V) vertical GaN-on-GaN Schottky barrier diode via oxygen plasma treatment

In this work, vertical gallium nitride (GaN) Schottky barrier diodes (SBDs) with an ultra-low turn-on voltage V-ON (0.37 V) were demonstrated. Due to the process of O-2 plasma treatment, GaON was formed on the surface of GaN and further modified the surface potential of the material surface, which made the V-ON decrease from 0.62 to 0.37 V. Spin-on-glass was deposited on top of devices to form the floating guard ring, which was used to improve the breakdown voltage to 681 V (at J = 1 A/cm(2)) by reducing the electric field distribution. The vertical GaN SBDs exhibit a specific on-resistance (R-ON) of 2.6 m Omega cm(2). Deterioration of the device under different stress time changes slightly showed great stability of the devices.