Device characteristics of scaled GaN/AlGaN MODFETs

Abstract
GaN/AlGaN MODFETs with gate-widths varying from 0.2 to 1 mm have been successfully fabricated, and the device characteristics have been systematically investigated. The epitaxial layers were grown directly on sapphire substrates by RF-assisted MBE. Thick-airbridge technology was employed in the fabrication of large gate periphery devices. Very stable and reproducible device characteristics have been obtained for devices with a total gate width of up to 1 mm. These device results demonstrated the excellent potential of GaN-based FETs as power cells for practical microwave applications.