High-Performance AlGaN Double Channel HEMTs with Improved Drain Current Density and High Breakdown Voltage.

In this work, AlGaN double channel heterostructure is proposed and grown by metal organic chemical vapor deposition (MOCVD), and high-performance AlGaN double channel high electron mobility transistors (HEMTs) are fabricated and investigated. The implementation of double channel feature effectively improves the transport properties of AlGaN channel heterostructures. On one hand, the total two dimensional electron gas (2DEG) density is promoted due to the double potential wells along the vertical direction and the enhanced carrier confinement. On the other hand, the average 2DEG density in each channel is reduced, and the mobility is elevated resulted from the suppression of carrier-carrier scattering effect. As a result, the maximum drain current density (I) of AlGaN double channel HEMTs reaches 473 mA/mm with gate voltage of 0 V. Moreover, the superior breakdown performance of the AlGaN double channel HEMTs is also demonstrated. These results not only show the great application potential of AlGaN double channel HEMTs in microwave power electronics but also develop a new thinking for the studies of group III nitride-based electronic devices.