• Journal of the Institute of Electronics Engineers of Korea SD
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• v.42 no.12
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• pp.103-112
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• 2005

In this paper, in order to derive the current-voltage characteristics of n-AlGaN/GaN HEMTs with the piezoelectric and spontaneous polarizations, we suggested analytical solutions for the two-dimensional Poisson equation in the AlGaN and GaN regions by taking into account the longitudinal field variation, field-dependent mobility, and the continuity condition of the channel current flowing in the quantum well. Obtained expressions for long and short channel devices would be applicable to the entire operating regions in a unified manner. Simulation results show that the drain saturation current increases and the cutoff voltage decreases as drain voltage increases. Compared with the conventional models, the present model seems to provide more reasonable explanation for the drain-induced threshold voltage roll-off and the channel length modulation effect.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.5
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• pp.21-28
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• 2007

In this paper, in order to derive the two-dimensional field effect of n-InAlAs/InGaAs HEMTs, we suggested analytical model by solving the two-dimensional Poisson's equation in both InAlAs and InGaAs regions by taking into account the longitudinal field variation, field-dependent mobility, and the continuity condition of the channel current flowing within the quantum well shaped channel. Derived expressions for long and short channel devices would be applicable to the entire operating regions in a unified manner. Simulation results show that the drain saturation current increases and the threshold voltage decreases as drain voltage increases. Compared with the conventional model, the present model may offer more reasonable explanation for the drain-induced threshold voltage roll-off, the Early effect, and the channel length modulation effect. Furthermore, it is expected that the proposed model would provide more reasonable theoretical basis for analyzing various long and short channel InAlAs/InGaAs HEMT devices.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.4
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• pp.354-358
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• 2004

In this thesis, an analytical model for Ⅰ-Ⅴ characteristics of an n-AlGaAs/GaAs Delta doped HEMT is proposed. 2-dimensional electron gas density, and conduction band edge profile are calculated from a self-consistent iterative solution of the Poisson equation. Parameters, e.g., the saturation velocity, 2-dimensional electron gas concentration, thickness of the doped and undoped layer(AlGaAs, GaAs, spacer etc.,) are in good agreement with the independent calculations.