High current density InN/AlN heterojunction field-effect transistor with a SiNx gate dielectric layer

InN/AlN metal-insulator-semiconductor heterojunction field-effect transistors with a gate-modulated drain current and a clear pinch-off characteristic have been demonstrated. The devices were fabricated using high-quality InN (26 nm)/AlN (100 nm) epifilms grown by plasma-assisted molecular-beam epitaxy on Si (111) substrates. The devices exhibited a current density higher than similar to 530 mA/mm with a 5 mu m gate length. The pinch-off voltage was at similar to-7 V with an associated drain leakage current less than 10 mu A/mm. The observed high current density may be attributed to the high sheet carrier density due to the large spontaneous polarization difference between InN and AlN. (c) 2007 American Institute of Physics.