Benjamin Iniguez

Continuous analytic I-V model for surrounding-gate MOSFETs

We present a continuous analytic current-voltage (I-V) model for cylindrical undoped (lightly doped) surrounding gate (SGT) MOSFETs. It is based on the exact solution of the Poissons equation, and the current continuity equation without the charge-sheet approximation, allowing the inversion charge distribution in the silicon film to be adequately described. It is valid for all the operation regions (linear, saturation, subthreshold) and traces the transition between them without fitting parameters, being ideal for the kernel of SGT MOSFETs compact models. We have demonstrated that the I-V characteristics obtained by this model agree with three-dimensional numerical simulations for all ranges of gate and drain voltages.

Explicit continuous model for long-channel undoped surrounding gate MOSFETs

We present an analytical and continuous dc model for cylindrical undoped surrounding-gate (SGT) MOSFETs in which the channel current is written as an explicit function of the applied voltages. The model is based on a new unified charge control model developed for this device. The explicit model shows good agreement with the numerical exact solution obtained from the new charge control model, which was previously validated by comparison with three-dimensional numerical simulations.

Charge-Based Modeling of Junctionless Double-Gate Field-Effect Transistors

We derived an analytical model for the junctionless double-gate metal-oxide-semiconductor field-effect transistor (DG MOSFET) device, the principle of which has been recently demonstrated. Despite some similarities with classical junction-based DG MOSFETs, the charge-potential relationships are quite different and cannot be merely mapped on existing multigate formalisms. This is particularly true for the technological parameters of interest where reported doping densities exceed 1019 cm-3 for 10- and 20-nm silicon channel thicknesses. Assessment of the model with numerical simulations confirms its validity for all regions of operation, i.e., from deep depletion to accumulation and from linear to saturation.

Modeling of nanoscale gate-all-around MOSFETs

We present a compact physics-based model for the nanoscale gate-all-around MOSFET working in the ballistic limit. The current through the device is obtained by means of the Landauer approach, being the barrier height the key parameter in the model. The exact solution of the Poissons equation is obtained in order to deal with all the operation regions tracing properly the transitions between them.

A short-channel DC SPICE model for polysilicon thin-film transistors including temperature effects

A semi-empirical analytical model for the DC characteristics of both n- and p-channel polysilicon thin-film transistors is described. The model is suitable for implementation in a SPICE circuit simulator. Our semi-empirical approach results in a physically based model with a minimum of parameters, which are readily related to the device structure and fabrication process. The intrinsic DC model describes all four regimes of operation: leakage, subthreshold, above threshold, and kink. The effects of temperature and channel length are also included in the short-channel model.

Analytical Model of the Threshold Voltage and Subthreshold Swing of Undoped Cylindrical Gate-All-Around-Based MOSFETs

Analytical physically based models for the threshold voltage, subthreshold swing, and drain-induced barrier lowering (DIBL) of undoped cylindrical gate-all-around MOSFETs have been derived based on an analytical solution of 2-D Poissons equation (in cylindrical coordinates) in which the mobile charge term has been included. Using the new model, threshold voltage, DIBL and subthreshold swing sensitivities to channel length, and channel thickness have been investigated. The models for DIBL, subthreshold swing, and threshold voltage rolloff parameters have been verified by comparison with 3-D numerical simulations; close agreement with the numerical simulations has been observed

Compact-Modeling Solutions For Nanoscale Double-Gate and Gate-All-Around MOSFETs

Compact-modeling principles and solutions for nanoscale double-gate and gate-all-around MOSFETs are explained. The main challenges of compact modeling for these devices are addressed, and different approaches for describing the electrostatics, the transport mechanisms, and the high-frequency behavior are explained. Several approximations used to derive analytical solutions of Poissons equation for doped and undoped devices are discussed, and the need for self-consistency with Schrodingers equation and with the current continuity equation resulting from the transport models is addressed. Several techniques to extend the compact modeling to the high-frequency regime and to study the RF performance, including noise, are presented and discussed

Two-Dimensional Analytical Threshold Voltage and Subthreshold Swing Models of Undoped Symmetric Double-Gate MOSFETs

We have developed analytical physically based models for the threshold voltage [including the drain-induced barrier lowering (DIBL) effect] and the subthreshold swing of undoped symmetrical double-gate (DG) MOSFETs. The models are derived from an analytical solution of the 2-D Poisson equation in which the electron concentration was included. The models for DIBL, subthreshold swing, and threshold voltage roll-off have been verified by comparison with 2-D numerical simulations for different values of channel length, channel thickness, and drain-source voltage; very good agreement with the numerical simulations has been observed

Fully-Depleted SOI CMOS Technology for Heterogeneous Micropower, High-Temperature or RF Microsystems

Based on an extensive review of research results on the material, process, device and circuit properties of thin-film fully depleted SOI CMOS, our work demonstrates that such a process with channel lengths of about 1 mum may emerge as a most promising and mature contender for integrated microsystems which must operate under low-voltage low-power conditions, at microwave frequencies and/or in the temperature range 200-350 degreesC

Explicit Analytical Charge and Capacitance Models of Undoped Double-Gate MOSFETs

An analytical, explicit, and continuous-charge model for undoped symmetrical double-gate (DG) MOSFETs is presented. This charge model allows obtaining analytical expressions of all total capacitances. The model is based on a unified-charge-control model derived from Poissons equation and is valid from below to well above threshold, showing a smooth transition between the different regimes. The drain current, charge, and capacitances are written as continuous explicit functions of the applied bias. We obtained very good agreement between the calculated capacitance characteristics and 2-D numerical device simulations, for different silicon film thicknesses.