• Journal of the Korea Institute of Information and Communication Engineering
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• v.19 no.6
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• pp.1399-1404
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• 2015

This paper analyzed the phenomenon of drain induced barrier lowering(DIBL) for the ratio of channel length vs. thickness of asymmetric double gate(DG) MOSFET. DIBL, the important secondary effect, is occurred for short channel MOSFET in which drain voltage influences on potential barrier height of source, and significantly affects on transistor characteristics such as threshold voltage movement. The series potential distribution is derived from Poisson's equation to analyze DIBL, and threshold voltage is defined by top gate voltage of asymmetric DGMOSFET in case the off current is 10^-7 A/m. Since asymmetric DGMOSFET has the advantage that channel length and channel thickness can significantly minimize, and short channel effects reduce, DIBL is investigated for the ratio of channel length vs. thickness in this study. As a results, DIBL is greatly influenced by the ratio of channel length vs. thickness. We also know DIBL is greatly changed for bottom gate voltage, top/bottom gate oxide thickness and channel doping concentration.

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.3
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• pp.149-155
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• 2010

Currently various safety tests are being performed in many countries with growing interest in vehicle safety. However the vehicles which have good safety performance in these tests could not secure the good performance in real car to car accident. So new test protocol using progressive deformable barrier (PDB) was proposed by EEVC in Europe, NHTSA in USA and some vehicle manufacturers, etc. The target of PDB test is to control partner protection in addition to self-protection on the same test. The proposal is to update current ECE R.94 frontal ODB test. So barrier, impact speed, overlap are changed to avoid bottoming-out in the test configuration. In this paper 3 different tests (R.94, EuroNCAP and PDB test) were carried out using current production vehicles with same structure. The results of these tests were compared to understand PDB test. As a result PDB test shows the highest vehicle deceleration and dummy injury because PDB offers a progressive increase in stiffness in depth and height. However vehicle intrusion was affected with rather test velocity than stiffness of deformable barrier. PDB deformation data is used for partner protection assessment using PDB software and it shows that the test vehicle is rather not aggressive.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.4
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• pp.805-810
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• 2016

The dependence of drain induced barrier lowering(DIBL) is analyzed for doping concentration in channel of asymmetric double gate(DG) MOSFET. The DIBL, the important short channel effect, is described as lowering of source barrier height by drain voltage. The analytical potential distribution is derived from Poisson's equation to analyze the DIBL, and the DIBL is observed according to top/bottom gate oxide thickness and bottom gate voltage as well as channel doping concentration. As a results, the DIBL is significantly influenced by channel doping concentration. DIBL is significantly increased by doping concentration if channel length becomes under 25 nm. The deviation of DIBL is increasing with increase of oxide thickness. Top and bottom gate oxide thicknesses have relation of an inverse proportion to sustain constant DIBL regardless channel doping concentration. We also know the deviation of DIBL for doping concentration is changed according to bottom gate voltage.

• Korean Journal of Materials Research
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• v.28 no.5
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• pp.268-272
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• 2018

An $Al_2O_3/AlN$ bilayer deposited on GaN by atomic layer deposition (ALD) is employed to prepare $Al_2O_3/AlN/GaN$ metal-insulator-semiconductor (MIS) diodes, and their interfacial properties are investigated using X-ray photoelectron spectroscopy (XPS) with sputter etch treatment and current-voltage (I-V) measurements. XPS analyses reveal that the native oxides on the GaN surface are reduced significantly during the early ALD stage, indicating that AlN deposition effectively clelans up the GaN surface. In addition, the suppression of Al-OH bonds is observed through the ALD process. This result may be related to the improved device performance because Al-OH bonds act as interface defects. Finally, temperature dependent I-V analyses show that the barrier height increases and the ideality factor decreases with an increase in temperature, which is associated with the barrier inhomogeneity. A Modified Richardson plot produces the Richardson constant of $A^{**}$ as $30.45Acm^{-2}K^{-2}$, which is similar to the theoretical value of $26.4Acm^{-2}K^{-2}$ for n-GaN. This indicates that the barrier inhomogeneity appropriately explains the forward current transport across the $Au/Al_2O_3/AlN/GaN$ interface.

• New Physics: Sae Mulli
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• v.68 no.12
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• pp.1288-1292
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• 2018

Using density functional theory calculations, we study the Schottky barrier (SB) change in a two-dimensional (2D) lateral heterostructure consisting of semiconducting $2H-MoS_2$ and the ferromagnetic metal $2H-VS_2$ by applying a uniaxial tensile strain from 0% to 10%. We find that the SB for holes is much smaller than that for electrons and that SB height decreases monotonically under increasing tensile strain. In particular, we find that a critical strain where the spin-up SB for holes is abruptly reduced to zero exists near a strain of 8%, implying that only the spin-up holes are allowed to flow through the $MoS_2-VS_2$ lateral heterostructure. Our results provide fundamental information and can be utilized to guide the design of 2D lateral heterostructure-based novel rectifying devices by using strain engineering.

• Animal Bioscience
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• v.35 no.6
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• pp.858-868
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• 2022

Objective: This study was conducted to evaluate the effects of dietary yeast hydrolysate (YH) supplementation on intestinal morphology, barrier, and anti-inflammatory functions of broilers. Methods: A total of 320 one day old male broilers were randomly allocated into four groups with eight replicates of ten broilers each. The broilers were supplemented with a basal diet (the control group) or basal diets adding 50, 100, 150 mg/kg YH, respectively. This trial lasted for 42 days. The orthogonal polynomial contrasts were used to determine the linear and quadratic effects of increasing levels of YH. Results: In our previous research, supplementing YH improved growth performance by enhancing body weight gain but decreased feed-to-gain ratio. In this study, compared with the control group, dietary YH addition linearly and quadratically decreased serum diamine oxidase activity (p<0.05). Additionally, supplementing YH linearly and/or quadratically decreased jejunal crypt depth (CD), tumor necrosis factor-alpha (TNF-α) concentration as well as mucin 2, interleukin-6 (IL-6), IL-1β, TNF-α, nuclear factor kappa B, and myeloid differentiation factor 88 gene expression levels (p<0.05). Whereas the jejunal villus height (VH), VH/CD, IL-10 concentration as well as zonula occludens-1 and IL-10 gene expression levels were linearly and/or quadratically increased by YH supplementation (p<0.05). Conclusion: Dietary YH supplementation improved intestinal morphology, barrier and anti-inflammatory functions while decreased intestinal permeability of broilers, which might be related with altering pertinent genes expression. This study provides evidence of YH as a promising feed additive for broilers.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.1332_1333
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• 2009

The electrical properties of an inorganic/organic heterojunction has been investigated by spin coating the p-type polymer poly(3,4 ethylenedioxythiophene) : poly(styrenesulfonate) (PEDOT:PSS) on an n-type gallium doping zinc oxide (GZO) film. Current-voltage (I-V) characteristics of the fabricated heterojunction diodes have a good rectifying characteristics. The barrier height is calculated 0.8 eV.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.1
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• pp.71-76
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• 1994

Schottky diodes have been fabricated using the SDB wafer, and their characteristics have been investigated. For comparison, conventional planar and etched most structure were made on the same substrate. The ideality factor and barrier height of the fabricated devices are found to be 1.03 and 0.77eV, respectively. Breakdown volttge of the etched mesa Schottky diode has been increased to 180V. whereas it is 90V for the planar diode. Schottky diode with an etched mesa exhibits twice improvement in breaktown voltage.

• Proceedings of the KIEE Conference
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• 2003.07e
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• pp.24-27
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• 2003

In this paper, We make experiment on two methode for GaAs MESFET with temperature variation. One method, we mesure gate leakage current at open source electrode. another we mesure gate leakage current at short source electrode. The difference of two current has been tested and provide that the existence of another source to Schottky barrier height against the image force lowering effect.

• Proceedings of the Korean Vacuum Society Conference
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• 2004.08a
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• pp.165-165
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• 2004