TY - GEN
T1 - Current degradation due to electromechanical coupling in GaN HEMT's
AU - Padmanabhan, Balaji
AU - Vasileska, Dragica
AU - Goodnick, Stephen
N1 - Funding Information:
This work was supported by a Grant from Army Research Laboratory . Program coordinator is Tsvetanka Zheleva. We also acknowledge the financial support from the NSF under Contract no. ECCS 0901251 .
Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012
Y1 - 2012
N2 - In this work we first report on a theoretical model which provides the gate voltage dependence of the piezoelectric polarization charge in GaN HEMT devices. The model utilizes a generalization of Gauss' law, imposing constraints on the electric displacement vector D. The constraint on D is given by the continuity of the perpendicular component of the displacement vector across an interface. Poisson's equation is then solved across various layers under proper boundary conditions for the applied bias. The piezoelectric polarization charge is reduced due to the electromechanical coupling compared to the uncoupled case. Under high sheet electron densities, the correction in the piezoelectric polarization charge is also lower due to smaller electric fields. The theoretical model is then incorporated in the particle-based device simulator and device transfer and output characteristics are calculated without and with the bias dependent polarization charge. We find that percentage change in drain current increases with larger negative bias on the gate, due to the larger vertical electric fields.
AB - In this work we first report on a theoretical model which provides the gate voltage dependence of the piezoelectric polarization charge in GaN HEMT devices. The model utilizes a generalization of Gauss' law, imposing constraints on the electric displacement vector D. The constraint on D is given by the continuity of the perpendicular component of the displacement vector across an interface. Poisson's equation is then solved across various layers under proper boundary conditions for the applied bias. The piezoelectric polarization charge is reduced due to the electromechanical coupling compared to the uncoupled case. Under high sheet electron densities, the correction in the piezoelectric polarization charge is also lower due to smaller electric fields. The theoretical model is then incorporated in the particle-based device simulator and device transfer and output characteristics are calculated without and with the bias dependent polarization charge. We find that percentage change in drain current increases with larger negative bias on the gate, due to the larger vertical electric fields.
KW - Electro-Mechanical coupling
KW - GaN HEMTs
KW - Polarization charges
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M3 - Conference contribution
AN - SCOPUS:84864950349
SN - 9781466562752
T3 - Technical Proceedings of the 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012
SP - 17
EP - 20
BT - Nanotechnology 2012
T2 - Nanotechnology 2012: Electronics, Devices, Fabrication, MEMS, Fluidics and Computational - 2012 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2012
Y2 - 18 June 2012 through 21 June 2012
ER -