• Journal of IKEEE
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• v.24 no.1
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• pp.194-199
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• 2020

The threshold voltage roll-off for an asymmetric junctionless double gate MOSFET is analyzed according to the top and bottom gate oxide thicknesses. In the asymmetric structure, the top and bottom gate oxide thicknesses can be made differently, so that the top and bottom oxide thicknesses can be adjusted to reduce the leakage current that may occur in the top gate while keeping the threshold voltage roll-off constant. An analytical threshold voltage model is presented, and this model is in good agreement with the 2D simulation value. As a result, if the thickness of the bottom gate oxide film is decreased while maintaining a constant threshold voltage roll-off, the top gate oxide film thickness can be increased, and the leakage current that may occur in the top gate can be reduced. Especially, it is observed that the increase of the bottom gate oxide thickness does not affect the threshold voltage roll-off.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.121-122
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• 2022

In this paper, the device performance with the structure of Nanosheet FET (NSFET) and FinFET is simulated through a three-dimensional device simulator. Current-voltage characteristics of NSFET and FinFET were simulated with respect to channel doping concentrations, and the performance such as threshold voltage and subthreshold swing extracted from the current-voltage characteristics was compared. NSFET flows more drain current and has a higher threshold voltage in current-voltage characteristics depending on channel doping concentration than that of FinFET. The subthreshold voltage swing (SS) of NSFET is steeper than that of FinFET

• JSTS:Journal of Semiconductor Technology and Science
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• v.15 no.6
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• pp.678-684
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• 2015

Near-threshold computing (NTC) is now regarded as a promising candidate for innovative power reduction, which cannot be achieved with conventional super-threshold computing (STC). However, performance degradation and vulnerability to process variation in the NTC regime are the primary concerns. In this paper, we propose a voltage- and frequency-tuning methodology for mitigating the process-variation-induced problems in NTC-based manycore architectures. To implement the proposed methodology, we build up multiple-voltage multiple-frequency (MVMF) islands and apply a voltage-frequency tuning algorithm based on the critical-path monitoring technique to reduce the effects of process variation and maximize energy efficiency in the post-silicon stage. Experimental results show that the proposed methodology reduces overall power consumption by 8.2-20.0%, compared to existing methods in variation-sensitive NTC environments.

• Journal of Electrical Engineering and Technology
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• v.13 no.6
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• pp.2421-2424
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• 2018

A direct measurement of an initiation carrier injection for a low voltage discharge is presented. A self-sustained pulsed discharge is utilized to characterize electrical responses of a glow discharge for varying amounts of injected initiation carriers. It is clearly demonstrated that the initiation carrier injection affects the ignition time and the breakdown voltage of the primary discharge. An abrupt reduction in the breakdown voltage for a $300{\mu}m$ gap pin-plate discharge is observed when a threshold carrier density of $3{\times}10^{11}cm^{-3}$ is injected and the breakdown voltage continues to decrease to 250 V with increasing the initiation carrier injection beyond the threshold density.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.517-520
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• 2008

A voltage-programming pixel circuit, which compensates the threshold voltage shift of TFTs and the degradation of OLED, is proposed for large sized a-Si:H active matrix organic light emitting diode (AMOLED) applications. Considering threshold voltage variation (or shift), OLED degradation and reverse bias annealing, HSPICE simulation results indicate that luminance error of every gray level is less than 0.4 LSB under the condition of +1V threshold voltage shift and from -0.2 LSB to 2.6 LSB within 30% degradation of OLED in the case of 40-inch full HDTV condition.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.529-530
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• 2005

A voltage driving AMOLED(Active Matrix Organic Light Emitting Diode) is useful for large-sized, high resolution OLED display. The conventional 2-TFTs, 1-CAP AMOLED circuit suffer from the threshold voltage variation of TFT. In this paper, a new AMOLED structure is proposed. It is composed of 5-TFTs and 2-capacitors. It is described that the operating principle and the characteristics of the proposed structure and is verified the performance by HSPICE simulation. The result of simulation shows that the effect of the threshold voltage variation in this circuit, is able to neglect.

• Journal of the Korean Institute of Telematics and Electronics
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• v.22 no.4
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• pp.51-58
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• 1985

A simple model for the impurity profile in an ion-implanted channel layer of an enhance-ment type IGFET is assumed and a simple expression for the threshold voltage is derived by the assumed impurity profile. In application, the concept of correction factor K is used and the value of threshold voltage is well agreed with experimental value. Also, 1-V character-istics curve is well agreed with experimental value. In addition, this program is packaged and is utilized.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.5
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• pp.982-988
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• 2012

This paper has presented the relation of scaling theory and threshold voltage of double gate(DG) MOSFET. In the case of conventional MOSFET, current and switching frequency have been analyzed based on scaling theory. To observe the possibility of application of scaling theory for threshold voltage of DGMOSFET, the change of threshold voltage has been observed and analyzed according to scaling theory. The analytical potential distribution of Poisson equation has been used, and this model has been already verified. To solve Poisson equation, charge distribution such as Gaussian function has been used. As a result, it has been observed that threshold voltage is grealty changed according to scaling factor and change rate of threshold voltages is traced for scaling of doping concentration in channel. This paper has explained for the best modified scaling theory reflected the influence of two gates as using weighting factor when scaling theory has been applied for channel length and channel thickness.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.1
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• pp.93-97
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• 2009

We analyzed voltage characteristics of toner particle type display according to particle layers and cell gap between two electrodes and ascertained the aging effects by measuring the response time of particles with and without aging process. The threshold/driving/breakdown voltage is proportional to layers of toner particles and cell gap and the response time at driving voltage is faster than that of threshold and breakdown voltage because of different q/m of color and black particles. The analysis of response time is a method of estimation of optical characteristics, driving voltage and particle lumping and these results are promoted by aging process. We use the laser and photodiode to measure response time and optical properties. It has not been studied and reported to analyze the relationship of response time, threshold/driving/breakdown voltage, lumping phenomena, cell gap, and aging process for toner particle type display.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.10
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• pp.2305-2309
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• 2010

In this paper, the variations of threshold voltage characteristics for ratio of channel length and thickness have been alanyzed for DG(Double Gate)MOSFET having top gate and bottom gate. Since the DGMOSFET has two gates, it has advantages that contollability of gate for current is nearly twice and SCE(Short Channel Effects) shrinks in nano devices. The channel length and thickness in MOSFET determines device size and extensively influences on SCEs. The threshold voltage roll-off, one of the SCEs, is large with decreasing channel length. The threshold voltage roll-off and drain induced barrier lowing have been analyzed with various ratio of channel length and thickness for DGMOSFET in this study.