Investigation of HfSiOX Passivation Effect on AlGaN/GaN HEMT

AlGaN/GaN-based high electron mobility Transistors (HEMTs) were fabricated on Si substrate. Surface passivation effect on AlGaN/GaN HEMTs was investigated with hafnium silicate (HfSiOx) passivation layer deposited by atomic layer deposition (ALD) at 250 °C. The DC current-voltage characteristics (I
_D
-V
_D
), pulsed I
_D
-V
_D
characteristics, and transfer characteristics of the device were compared before and after passivation. The enhancement of IDMAX and GMMAX with better gate controllability as well as significant reduction of current degradation phenomenon due to the suppression of surface states, was observed in the passivated (HfSiO
_X
) HEMT compared to unpassivated device.