S.A. Chevtchenko, E. Cho, F. Brunner, E. Bahat-Treidel, and J. Würfl

Published in:

Appl. Phys. Lett., vol. 100, no. 223502 (2012).

Abstract:

An example of GaN buffer structure optimization in AlGaN/GaN heterojunction field-effect transistors is demonstrated. Transistors fabricated on four epitaxial structures with buffer consisting of unintentionally doped GaN channel (35 nm or 100 nm) and carbon doped GaN:C layers (≈1×10¹⁸ cm^-3 or ≈1×10¹⁷ cm^-3) are compared. As the criteria for optimization off-state breakdown voltage (V_br) and drain current dispersion are used. The observed trade-off between the two parameters and dependency of V_br on the carbon concentration and on the channel thickness are explained by a potential barrier formed due to GaN:C part of the buffer.

© 2012 American Institute of Physics. 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 American Institute of Physics.

Full version in pdf-format.