Gd₂O₃/GaN metal-oxide-semiconductor field-effect transistor

Gd₂O₃ has been deposited epitaxially on GaN using elemental Gd and an electron cyclotron resonance oxygen plasma in a gas-source molecular beam epitaxy system. Cross-sectional transmission electron microscopy shows a high concentration of dislocations which arise from the large lattice mismatch between the two materials. GaN metal-oxide-semiconductor field-effect transistors (MOSFETs) fabricated using a dielectric stack of single crystal Gd₂O₃ and amorphous SiO₂ show modulation at gate voltages up to 7 V and are operational at source drain voltages up to 80 V. This work represents demonstrations of single crystal growth of Gd₂O₃ on GaN and of a GaN MOSFET using Gd₂O₃ in the gate dielectric.