Realization of AlGaN/GaN HEMTs on Si‐on‐polySiC substrates

Abstract

AlGaN/GaN High Electron Mobility Transistors have been realized on resistive Si(111)/SiO2/polySiC substrates. The epitaxial structures were grown by Molecular Beam Epitaxy. The structural, optical, and electrical properties of these films are studied and compared with those of reference heterostructures grown on thick Si(111) substrates. Channel mobility of 1470 cm2/Vs at room temperature and sheet carrier density of 6.65x1012 cm–2 have been achieved. Field effect transistors with 3.6 µm x 100 µm gates have been fabricated on these layers and exhibit a drain current superior to 450 mA/mm and a transconductance of 123 mS/mm. Furthermore, to evaluate the influence of heat transfer onto electrical properties, the resistance change with the power dissipated inside Transmission Line Measurement devices has been compared with those in devices realized with layers grown on thick Si(111) and 4H‐SiC substrates. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Enhancement- and depletion-mode AlGaN/GaN HEMTs on 3C-SiC(111)/Si(111) pseudosubstrates

“…Such a material is SiC, firstly employed by Takeuchi and Davis . Later, micrometer thick 3C‐SiC(111) layers were used for the same purpose . Albeit, it was shown that for reliable heteroepitaxial growth and device fabrication thick silicon carbide layers are not necessary .…”