An analytical expression for Fermi level versus sheet carrier concentration for HEMT modeling

“…The above equation is having the assumption that the fermi level variation with electron density inside the quantum well is neglected [17]. However, considering the above equation is plausible when the 2DEG is analyzed at zero gate bias.…”

Section: Dependence Of N S On Eigenenergy Levelsmentioning

confidence: 99%

Modeling and simulation of oxide dependent 2DEG sheet charge density in AlGaN/GaN MOSHEMT

et al. 2015

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Oxide dielectric present in metal oxide semiconductor high electron mobility transistor plays an important role during formation of two dimensional electron gas (2DEG). The sheet charge concentration (n s ) is dependent on the Eigenenergy states present in triangular quantum well at AlGaN/GaN interface. The energy states are in fact functions of vertical electric field at the edge of the well. Therefore in this paper a model is developed to find out Electric field and flat-band voltage (V T ) by adopting energy band approach to incorporate oxide parameters in it unlike the conventional method of solving Poisson's equation, which is the uniqueness of this paper. The Eigenenergy states are dependent non-linearly on electric field. In the present case, three quantum states in the well are considered along with the Fermi-Dirac distribution function to obtain n s . The dependence of 2DEG density, electric field and flat-band voltage on the oxide parameters such as thickness and electrical permittivity is analyzed. With respect to thickness in SiO 2 and Al 2 O 3 , n s shows inverse relationship; whereas in HfO 2 it is direct due to positive charges accumulated at oxide/barrier interface. To the best of author's knowledge the work is first of its kind and due to lack of experimental data; the obtained results are compared with TCAD results to validate the model.

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“…However, the Fermi level can be expressed by a second-order expression as given by Kola et al [13], which gives a good fitting to the numerical solution of eq. (1), where E F is defined as…”

Section: Dependence Of N S On Oxide Thicknessmentioning

confidence: 99%

“…k 1 , k 2 and k 3 have been calculated as in [13]. Using eqs (9) and (1) and solving for n s , we get…”

Section: Dependence Of N S On Oxide Thicknessmentioning

confidence: 99%

Impact of oxide thickness on gate capacitance – Modelling and comparative analysis of GaN-based MOSHEMTs

2015

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In this paper, we have developed a mathematical model to predict the behaviour of gate capacitance and threshold voltage with nanoscale variation of oxide thickness in AlInN/GaN and AlGaN/GaN metal oxide semiconductor high electron mobility transistor (MOSHEMT). The results obtained from the model are compared with the TCAD simulation results to validate the model. It is observed that AlInN/GaN MOSHEMT has an advantage of significant decrease in gate capacitance up to 0.0079 pF/μm 2 with increase in oxide thickness up to 5 nm as compared to conventional AlGaN/GaN MOSHEMT. This decrease in gate capacitance in AlInN/GaN MOSHEMT reduces the propagation delay and hence improves the RF performance of the device.

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An analytical expression for Fermi level versus sheet carrier concentration for HEMT modeling

Cited by 109 publications

References 4 publications

A compact analytical I–V model of AlGaAs/InGaAs/GaAs p-HEMTs based on non-linear charge control model

A compact analytical I–V model of AlGaAs/InGaAs/GaAs p-HEMTs based on non-linear charge control model

Modeling and simulation of oxide dependent 2DEG sheet charge density in AlGaN/GaN MOSHEMT

Impact of oxide thickness on gate capacitance – Modelling and comparative analysis of GaN-based MOSHEMTs

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