Growth and characterization of AlGaN/AlN/GaN HEMTs on 100-mm-diameter epitaxial AlN/sapphire templates

Al/sub 0.26/Ga/sub 0.74/N/AlN/GaN heterostructures with a 1-nm-thick AIN interfacial layer were grown on 100-mm-diameter epitaxial AIN/sapphire templates by metalorganic vapor phase epitaxy. They exhibited 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 sheet carrier density of approximately 1 /spl times/ 10/sup 13//cm/sup 2/. High-electron-mobility transistors were successfully fabricated on the epitaxial wafers. The device exhibited a high drain current density of 832 mA/mm and high extrinsic transconductance of 189 mS/mm.