High-sheet-charge-carrier-density AllnN/GaN field-effect transistors on Si(111)

Abstract

AlInN/GaN heterostructures have been proposed to possess advantageous properties for field-effect transistors (FETs) over AlGaN/GaN [Kuzmik, IEEE Electron Device Lett. 22, 501 (2001); Yamaguchi et al., Phys. Status Solidi A 188, 895 (2001)]. A major advantage of such structures is that AlInN can be grown lattice-matched to GaN while still inducing high charge carrier densities at the heterointerface of around 2.7 × 1013 cm-3 by the differences in spontaneous polarization. Additionally, it offers a higher band offset to GaN than AlGaN. We grew AlInN FET structures on Si(111) substrates by metalorganic chemical vapor phase epitaxy with In concentrations ranging from 9.5% to 24%. Nearly lattice-matched structures show sheet carrier densities of 3.2 × 1013 cm-2 and mobilities of ∼406 cm2/V s. Such Al0.84In0.16N FETs have maximum dc currents of 1.33 A/mm for devices with 1 μm gate length. © 2004 American Institute of Physics.