Barrier layer downscaling of InAIN/GaN HEMTs

In this study we have investigated heterojunctions on sapphire with barrier thicknesses between 13 nm and 5 nm maintaining a high output current. The results indicate that InAlN/GaN HEMT device structures can be reliably designed and fabricated with barrier layer thicknesses approaching the tunnelling thickness and approaching enhancement mode characteristics. Using Al
₂
O
₃
as high-k gate dielectric also high aspect ratio MOSHEMTs could be designed with comparable characteristics to MESHEMTs of the same barrier thickness. This is an ongoing study and results on further barrier downscaling experiments will be presented.