MgO/p-GaN enhancement mode metal-oxide semiconductor field-effect transistors

We report the initial demonstration of an enhancement mode MgO/p-GaN metal-oxide-semiconductor field-effect transistor (MOSFET) utilizing Si+ ion-implanted regions under the source and drain to provide a source of minority carriers for inversion. The breakdown voltage for an 80-nm-thick MgO gate dielectric was similar to14 V, corresponding to a breakdown field strength of 1.75 MV cm(-1) and the p-n junction formed between the p-epi and the source had a reverse breakdown voltage >15 V. Inversion of the channel was achieved for gate voltages above 6 V. The maximum transconductance was 5.4 muS mm(-1) at a drain-source voltage of 5 V, comparable to the initial values reported for GaAs MOSFETs. (C) 2004 American Institute of Physics.