Effect of barrier recess on transport and electrostatic interface properties of GaN-based normally-off and normally-on metal oxide semiconductor heterostructure field effect transistors
M. Capriottia, E. Bahat-Treidelb, C. Fleurya, O. Bethgea, C. Ostermaierc, M. Rigatoa, S.L.C. Lancastera, F. Brunnerb, H. Detza, O. Hiltb, J. Würflb, D. Poganya, G. Strassera
Published in:
Solid-State Electron., vol. 125, pp. 118-124 (2016).
Abstract:
We perform a comprehensive electrical transport and physical characterization of metal oxide semiconductor heterostructure field effect transistors with ZrO2 gate dielectrics, having partially (referred here as MOS-HFET) and fully (here called true-MOS-FET) recessed GaN/AlGaN/GaN barrier, giving normally-on and normally-off behavior, respectively. The mobility of the MOS-HFETs decreases with the proximity of the Coulomb scattering centers, situated at the ZrO2/AlGaN interface. The effect of the etching procedure and ZrO2 deposition on the formation of the interfacial charges, Nint, is evaluated by X-ray Photoelectron Spectroscopy and by fitting the threshold voltage values to numerical model. For the both device types, the extracted value of Nint lies within 15% around 2.8 × 1013 cm-2, which is of the order of polarization charge, showing that our low-damage three step etching procedure does not introduce extra interface states.
a Vienna University of Technology, Floragasse 7, A-1040 Vienna, Austria
b Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, 12489 Berlin, Germany
c Infineon Technologies Austria AG, Siemensstraße 2, A-9500 Villach, Austria
Copyright © 2016 Elsevier Ltd. All rights reserved. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the Elsevier Ltd.
Full version in pdf-format.