Growth and fabrication of AlGaN/GaN HEMT based on Si(1 1 1) substrates by MOCVD

Abstract

AlGaN/GaN high electron mobility transistor (HEMT) hetero-structures were grown on the 2-in Si (111) substrate using metal-organic chemical vapor deposition (MOCVD). Low-temperature (LT) AlN layers were inserted to relieve the tension stress during the growth of GaN epilayers. The grown AlGaN/GaN HEMT samples exhibited a maximum crack-free area of 8mm×5mm, XRD GaN (0002) full-width at half-maximum (FWHM) of 661arcsec and surface roughness of 0.377nm. The device with a gate length of 1.4μm and a gate width of 60μm demonstrated maximum drain current density of 304mA/mm, transconductance of 124mS/mm and reverse gate leakage current of 0.76μA/mm at the gate voltage of −10V.