High voltage AlGaN/GaN Schottky barrier diode employing the inductively coupled plasma-chemical vapor deposition SiO2 passivation

The SiO₂ passivation using the inductively coupled plasma-chemical vapor deposition(ICP-CVD) was proposed for the high voltage AlGaN/GaN Schottky barrier diode(SBD). The ICP-CVD is well known for the high-density remote plasma, so this method reduces the plasma damage on the surface of semiconductor. Experimental results showed that the SiO₂ passivation improved the electrical characteristics of AlGaN/GaN SBDs. The specific on-resistance was decreased from 15.1 mldrldrcm² to 13.2 mldrldrcm², and the reverse breakdown voltage increased from 87.5 V to 497.0 V. Schottky barrier height was also increased from 0.64 to 0.92. The figure-of-merit (VB²/R_ON) of the SiO² passivated device was 18.71 MW/cm². These improvements of the proposed device were attributed to the suppression of electron trapping at the surface states.