Abstract
A/sub 0.26/Ga/sub 0.74/N/AlN/GaN heterostructures with 1-nm-thick AlN interfacial layers were grown on 100-mm-diameter epitaxial AlN/sapphire templates and sapphire substrates by metalorganic vapor phase epitaxy (MOVPE). Very high Hall mobilities of approximately 2100 cm/sup 2//Vs at room temperature and approximately 25000 cm/sup 2//Vs at 15 K with a 2DEG density of approximately 1/spl times/ 10/sup 13//cm/sup 2/ were uniformly obtained for AlGaN/ AlN/GaN heterostructures on 100-mm-diameter epitaxial AIN/ sapphire templates. High-electron-mobility transistors (HEMTs) were successfully fabricated on the AlGaN/AlN/GaN film on the epitaxial AIN/sapphire template. The fabricated devices exhibited good pinch-off characteristics and a very high intrinsic transconductance of 496 mS/mm.