Inversion Charge Distribution Function Research Articles

Quantum Modelling of Nanoscale Silicon Gate-All-Around Field Effect Transistor

The paper introduces an analytical model for gate all around (GAA) or Surrounding Gate Metal Oxide Semiconductor Field Effect Transistor (SG-MOSFET) inclusive of quantum mechanical effects. The classical oxide capacitance is replaced by the capacitance incorporating quantum effects by including the centroid parameter. The quantum variant of inversion charge distribution function, inversion layer capacitance, drain current, and transconductance expressions are modeled by employing this model. The established analytical model results agree with the simulated results, verifying these models' validity and providing theoretical supports for designing and applying these novel devices.

Analytical Quantum Model for Germanium Channel Gate-All-Around (GAA) MOSFET

The paper proposes analytical model for Gate-All-Around Metal Oxide Semiconductor Field Effect Transistor (GAA-MOSFET) for germanium channel including quantum mechanical effects. It is achieved by solving coupled Schrodinger-Poisson’s equation using variational approach. The proposed model takes quantum confinement effects to obtain charge centroid and inversion charge model. By using these models the quantum version of inversion layer capacitance, inversion charge distribution function and Drain current expressions are modelled and the performance evaluation of the developed model is compared with Silicon channel GAA-MOSFET. Analytically modelled expressions are verified by comparing the model with simulation results.

A new explicit and analytical model for square Gate-All-Around MOSFETs with rounded corners

The scaling of MOSFET transistors makes the use of new device geometries, such as multigate FETs, a need to solve the limitations of the conventional bulk technology. In this context we introduce an analytical model for square Gate All Around (GAA) MOSFETs with rounded corners including quantum effects. The modeling of rounded corners in GAA and FinFET devices is imperative because there are no perfectly square corners in the cross-section of real devices. In this model the 2D inversion charge distribution function (ICDF) is described analytically for devices of different sizes and for different operation regimes. The model reproduces accurately simulated data obtained with a state-of-the-art simulator that solves self-consistently the Poisson and Schrödinger equations in the devices under consideration. The analytical ICDF is used to better understand the device physics and to calculate the inversion charge centroid and the gate-to-channel capacitance for different device geometries and biases for modeling purposes.

Modeling and simulation of nanoscale tri-gate MOSFETs including quantum effects

Quantum effects are predominant in tri-gate MOSFETs, so a model should be developed. For the first time, this paper presents the analytical model for quantization effects of thin film silicon tri-gate MOSFETs by using variational approach. An analytical expression of the inversion charge distribution function (ICDF) or wave function for the tri-gate MOSFETs has been obtained. This obtained ICDF is used to calculate the important device parameters, such as the inversion charge centroid and inversion charge density. The results are validated against with the simulation data.

A Compact Quantum Model for Cylindrical Surrounding Gate MOSFETs using High-k Dielectrics

In this paper, an analytical model for Surrounding Gate (SG) metal-oxide- semiconductor field effect transistors (MOSFETs) considering quantum effects is presented. To achieve this goal, we have used variational approach for solving the Poission and Schrodinger equations. This model is developed to provide an analytical expression for inversion charge distribution function for all regions of device operation. This expression is used to calculate the other important parameters like inversion charge density, threshold voltage, drain current and gate capacitance. The calculated expressions for the above parameters are simple and accurate. This paper also focuses on the gate tunneling issue associated with high dielectric constant. The validity of this model was checked for the devices with different dimensions and bias voltages. The calculated results are compared with the simulation results and they show good agreement.

New Analytical Model for Nanoscale Tri-Gate SOI MOSFETs Including Quantum Effects

In this paper, an analytical model for tri-Gate (TG) MOSFETs considering quantum effects is presented. The proposed model is based on the analytical solution of Schrodinger-Poisson's equation using variational approach. An analytical expression of the inversion charge distribution function (ICDF) or wave function for the TG MOSFETs has been developed. This obtained ICDF is used to calculate the device parameters, such as the inversion charge centroid, threshold voltage, inversion charge, gate capacitance, and drain current. These parameters are modeled for various device dimensions and applied bias. The results are validated against the TCAD simulation results.

Analytical modeling of quantization effects in surrounding-gate MOSFETs

Purpose – The purpose of this paper is to present an analytical model and simulation for cylindrical gate all around MOSFTEs including quantum effects. Design/methodology/approach – To incorporating the impact of quantum effects, the authors have used variational method for solving the Poisson and Schrodinger equations. The accuracy of the results obtained using this model is verified by comparing them with simulation results. Findings – This model is developed to provide an analytical expression for inversion charge distribution function for all regions of device operation. This expression is used to calculate the other important parameters like inversion charge centroid, threshold voltage, inversion charge, gate capacitance and drain current. The calculated expressions for the above parameters are simple and accurate. The validity of this model was checked for the devices with different dimensions and bias voltages. Practical implications – Simulation based on the compact physical models reduces the cost of developing a sophisticated fabrication technology and shortens the time-to-market. They may also be utilized to explore innovative device structures. Originality/value – This paper presents, for the first time, a compact quantum analytical model for cylindrical surrounding gate MOSFETs which predicts the device characteristics reasonably well over the entire range of device operation (above threshold as well as sub-threshold region).

Modeling and simulation of centroid and inversion charge density in cylindrical surrounding gate MOSFETs including quantum effects

An analytical model for surrounding gate metal—oxide—semiconductor field effect transistors (MOSFETs) considering quantum effects is presented. To achieve this goal, we have used a variational approach for solving the Poissonand Schrodinger equations. This model is developed to provide an analytical expression for the inversion charge distribution function for all regions of the device operation. This expression is used to calculate the other important parameters like the inversion charge centroid, threshold voltage and inversion charge density. The calculated expressions for the above parameters are simple and accurate. The validity of this model was checked for the devices with different device dimensions and bias voltages. The calculated results are compared with the simulation results and they show good agreement.

ANALYTICAL MODELING OF DRAIN CURRENT, CAPACITANCE AND TRANSCONDUCTANCE IN SYMMETRIC DOUBLE-GATE MOSFETs CONSIDERING QUANTUM EFFECTS

An analytical model for double-gate (DG) MOSFETs considering quantum mechanical effects is proposed in this paper. Schrödinger and Poisson's equations are solved simultaneously using a variational approach. Solving the Poisson and Schrödinger equations simultaneously reveals quantum effects (QME) that influence the performance of DG MOSFETs. This model is developed to provide an analytical expression for inversion charge distribution function for all regions of device operation. This expression is used to calculate the other important parameters like inversion layer centroid, inversion charge, gate capacitance, drain current and transconductance. We systematically evaluate and analyze the parameters of DG MOSFETs considering QME. The analytical solutions are simple, accurate and provide good physical insight into the quantization caused by quantum confinement under various gate biases. The analytical results of this model are verified by comparing the data obtained with one-dimensional self-consistent numerical solutions of Poisson and Schrödinger equations known as SCHRED.

An analytical model for square GAA MOSFETs including quantum effects

In this paper we introduce an analytical model for square Gate-All-Around (GAA) MOSFETs including quantum effects. With the model developed, it is possible to provide an analytical description of the 2D inversion charge distribution function (ICDF) in square GAA MOSFETs of different sizes and for all the operational regimes. The accuracy of the model is verified by comparing the data with that obtained by means of a 2D numerical simulator that self-consistently solves the Poisson and Schrödinger equations. The expressions presented here are useful to achieve a good description of the physics of these transistors; in particular, of the quantization effects on the inversion charge. The analytical ICDF obtained is used to calculate important parameters from the device compact modeling viewpoint, such as the inversion charge centroid and the gate-to-channel capacitance, which are modeled for different device geometries and biases. The model presented accurately reproduces the simulation results for the devices under study and for different operational regimes.