Yong Hyeon Shin

Channel doping-dependent analytical model for symmetric double gate metal-oxide-semiconductor field-effect transistor. I. Extraction of subthreshold characteristics

An analytical 2D model of subthreshold current (IDSsub), subthreshold swing (Ssub), and threshold voltage (VTH) roll-off with a variation of channel doping concentration (NA) for symmetric double gate (DG) metal-oxide-semiconductor field-effect transistor (MOSFET) is presented. First of all, the channel potential is obtained by solving the 2D Poissons equation with the help of the evanescent method. Based on the obtained channel potential, IDSsub, Ssub, and VTH roll-off expressions are derived in the analytical model. It is shown that the subthreshold characteristics predicted by the analytical model are in good agreement with commercially available 2D numerical simulation results for different channel length (L), channel film thickness (tsi), gate oxide (tox), and NA.

Modeling of positional plasma characteristics by inserting body tube of optical emission spectroscopy for plasma assisted atomic layer deposition system

Based on a measurable range of optical emission spectroscopy (OES), the modeling of plasma characteristic is investigated depending on the position of incident angle of OES. In this work, OES is installed in the viewpoint of the plasma assisted atomic layer deposition (PA-ALD) system and plasma characteristic is measured using OES. For the enhancement to obtain the plasma characteristic information, the measurement scheme by inserting body tube in front of optical fiber is developed to receive the limited light of plasma. Since a normal optical fiber is not possible to measure plasma uniformity, the proposed scheme can measure a gap of plasma intensity for each region of a wafer. The detailed analytic model is developed by using the analysis between the plasma intensity and the characteristic of PA-ALD. This scheme can allow us to improve the accuracy of a plasma diagnosis, the detection capability of plasma abnormality and the manufacturability.

Channel doping-dependent analytical model for symmetric double gate metal-oxide-semiconductor field-effect transistor. II. Continuous drain current model from subthreshold to inversion region

Based on the subthreshold region model described in Paper I [Cho et al., J. Appl. Phys. 113, 214506 (2013)], a continuous drain current model with a variation of channel doping concentration (NA) for symmetric double gate metal-oxide-semiconductor field-effect transistor is presented. Here, the inversion region drain current model is derived by solving the long-channel 1D Poissons equation due to the strong screening effects by electrons. The continuous drain current model is obtained by interpolating the subthreshold region model and the inversion region model. Since the subthreshold region model includes the short-channel effects, it is shown that the continuous drain current modeling results are in good agreement with commercially available 2D numerical simulation results from the subthreshold to the inversion region in the wide range of NA.

An analytical avalanche breakdown model for double gate MOSFET

Abstract An analytical model of avalanche breakdown for double gate (DG) metal-oxide-semiconductor field-effect transistor (MOSFET) is presented. First of all, the effective mobility (μeff) model is defined to replace the constant mobility model. The channel length modulation (CLM) effect is modeled by solving the Poisson’s equation. The avalanche multiplication factor (M) is calculated using the length of saturation region (ΔL). It is shown that the avalanche breakdown characteristics calculated from the analytical model agree well with commercially available 2D numerical simulation results. Based on the results, the reliability of the DG MOSFET can be estimated using the proposed analytical model.

A compact quantum correction model for symmetric double gate metal-oxide-semiconductor field-effect transistor

A compact quantum correction model for a symmetric double gate (DG) metal-oxide-semiconductor field-effect transistor (MOSFET) is investigated. The compact quantum correction model is proposed from the concepts of the threshold voltage shift (ΔVTH QM ) and the gate capacitance (Cg ) degradation. First of all, ΔVTH QM induced by quantum mechanical (QM) effects is modeled. The Cg degradation is then modeled by introducing the inversion layer centroid. With ΔVTH QM and the Cg degradation, the QM effects are implemented in previously reported classical model and a comparison between the proposed quantum correction model and numerical simulation results is presented. Based on the results, the proposed quantum correction model can be applicable to the compact model of DG MOSFET.

Modeling of Subthreshold Characteristics for Double Gate MOSFET Using Neural Networks and Genetic Algorithm

As the metal-oxide-semiconductor field-effect transistor (MOSFET) technology has been developed, the short-channel effects become significant. To ov ercome these limitations, double gate (DG) MOSFET has been considered and predicting the device characteristics according to device parameters has been important. In this paper, we present the neural networks (NNET) modeling methodology to predict subthreshold characteristics such as threshold voltage (VTH) and subthreshold swing (SSUB) for DG MOSFET. After the NNET model is established, the genetic algorithm (GA) is used to find th e device parameters’ design space.

Green's function based 2-D MOSFET modeling for random dopant fluctuation

Random dopant fluctuation (RDF) in MOSFET has been an issue recently due to the scaling down of CMOS process. Impedance field method has mainly used as a solution to predict effects of RDF previously. In addition, a new model, which converts a Poissons equation into a Greens function based form, estimates inhomogeneous term of differential equation through charge distribution. In this paper, a Greens function based 2-D MOSFET model is proposed. The model starts from the Poissons equation to obtain the initial conditions and then sum of Greens function based formula and Laplace equation provide voltage distribution, charge distribution, and drive current as the modeling results. We also verify its effectiveness through the comparison with TCAD simulation results.