2H-AlGaN/GaN HEMTs on 3C-SiC(111)/Si(111) Substrates
We present the realization of high electron mobility transistors (HEMTs) based on AlGaN/GaN heterostructures grown on silicon substrates using a SiC transition layer. The growth of AlGaN/GaN heterostructures on Si (111) was performed using metalorganic chemical vapour deposition (MOCVD). The (111) SiC transition layer was realized by low pressure CVD and prevented Ga-induced meltback etching and Si-outdiffusion in the subsequent MOCVD growth. The two-dimensional electron gas (2DEG) formed at the AlGaN/GaN interface showed an electron sheet density of 1.5x1013 cm-3 and a mobility of 870 cm²/Vs proving the high structural quality of the heterostructure. Device processing was done using electron beam lithography. DC and RF characteristics were analysed and showed a peak cut-off frequency as high as 6 GHz for a 1.2 µm gate HEMT.
Anton J. Bauer, Peter Friedrichs, Michael Krieger, Gerhard Pensl, Roland Rupp and Thomas Seyller
K. Tonisch et al., "2H-AlGaN/GaN HEMTs on 3C-SiC(111)/Si(111) Substrates ", Materials Science Forum, Vols. 645-648, pp. 1219-1222, 2010