Impact of Buffer Composition on the Dynamic On-State Resistance of High-Voltage AlGaN/GaN HFETs

O. Hilt, E. Bahat-Treidel, E. Cho, S. Singwald and J. Würfl

Ferdinand-Braun-Institut, Leibniz-Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Straße 4, D-12489 Berlin, Germany

Published in:
24th Int. Symp. on Power Semiconductor Devices and ICs, Bruges, Belgium, Jun. 3-7, pp. 345-348 (2012).
© Copyright 2012 IEEE - 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 IEEE.

Abstract:
Switching experiments with normally-off GaN-HFETs using a carbon-doped GaN buffer or an AlGaN buffer showed very different magnitudes of increased dynamic on-state resistance. The dynamic on-state resistance is analyzed for variations in buffer composition and set into relation to the buffer voltage-blocking strength. Also, the impact of p-GaN gate normally-off and Schottky-gate normally-on device technologies on the dispersion is studied. It is concluded that a buffer with less trap sites and lower breakdown strength is more favorable for high-voltage switching than a buffer with incorporated acceptors to increase the buffer breakdown strength.

Keywords:
GaN; normally off; dynamic on-state resistance; dispersion; switching.

Full version in pdf-format.