Compatibility of AlN/SiNx Passivation With LPCVD-SiNx Gate Dielectric in GaN-Based MIS-HEMT

In this letter, we demonstrate an integrated process that illustrates the compatibility of AlN/SiNx passivation with high-performance (i.e. low leakage and high breakdown) low-pressure chemical vapor deposition (LPCVD) SiN
_x
gate dielectric for GaN-based MIS-HEMT. It is shown that the AlN/SiNx passivation structure maintains its superior capability of suppressing the current collapse after enduring high temperature of 780 °C during the LPCVD-SiN
_x
deposition. The AlN/SiN
_x
passivation is shown to be significantly better than the LPCVD-SiN
_x
passivation by delivering small dynamic R
_ON
degradation, especially under high drain bias switching with V
_DS
> 100 V.