• Journal of the Semiconductor & Display Technology
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• v.18 no.2
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• pp.29-31
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• 2019

The ZTO/p-Si thin film was produced and investigated for tunneling phenomena caused by the interface characteristics of the depletion layer. ZTO thin film was deposited and heat treated to produce barrier potentials by the depletion layer. The negative resistance characteristics were shown in the thin film of ZTO heat treated at $100^{\circ}C$, and the insulation properties were the best. Current decreased in the negative voltage direction by nonlinear show key characteristics, and current decreased in tunneling phenomenon by negative resistance in the positive voltage direction. Heat treated at $100^{\circ}C$, the ZTO thin film has increased barrier potential in the areas of the depletion layer and therefore the current has increased rapidly. The current has decreased again as we go beyond the depletion layer. Therefore, tunneling can be seen to make insulation better. In the ZTO thin film heat treated at $70^{\circ}C$ without tunneling, leakage current occurred as current increased at positive voltage. Therefore, tunneling effects by negative resistance were found to enhance insulation properties electrically.

• Korean Journal of Materials Research
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• v.29 no.7
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• pp.408-411
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• 2019

ZTO/n-Si thin film is produced to investigate tunneling phenomena by interface characteristics by the depletion layer. For diversity of the depletion layer, the thin film of ZTO is heat treated after deposition, and the gpolarization is found to change depending on the heat treatment temperature and capacitance. The higher the heat treatment temperature is, the higher the capacitance is, because more charges are formed, the highest at $150^{\circ}C$. The capacitance decreases at $200^{\circ}C$ ZTO heat treated at $150^{\circ}C$ shows tunneling phenomena, with low non-resistance and reduced charge concentration. When the carrier concentration is low and the resistance is low, the depletion layer has an increased potential barrier, which results in a tunneling phenomenon, which results in an increase in current. However, the ZTO thin film with high charge or high resistance shows a Schottky junction feature. The reason for the great capacitance increase is the increased current due to tunneling in the depletion layer.

• JSTS:Journal of Semiconductor Technology and Science
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• v.11 no.4
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• pp.287-294
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• 2011

In this paper, two competing mechanisms determining drain current of tunneling field-effect transistors (TFETs) have been investigated such as band-to-band tunneling and drift. Based on the results, the characteristics of TFETs have been discussed in the tunneling-dominant and drift-dominant region.

• Journal of Magnetics
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• v.14 no.1
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• pp.11-14
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• 2009

We investigated the I-V curves and differential tunneling conductance of two, CoFeB/MgO/CoFeB-based, magnetic tunnel junctions (MTJs): one with a low tunneling magnetoresistance (TMR; 22%) and the other with a high TMR (352%). This huge TMR difference was achieved by different MgO sputter conditions rather than by different annealing or deposition temperature. In addition to the TMR difference, the junction resistances were much higher in the low-TMR MTJ than in the high-TMR MTJ. The low-TMR MTJ showed a clear parabolic behavior in the dI/dV-V curve. This high resistance and parabolic behavior were well explained by the Simmons' simple barrier model. However, the tunneling properties of the high-TMR MTJ could not be explained by this model. The characteristic tunneling properties of the high-TMR MTJ were a relatively low junction resistance, a linear relation in the I-V curve, and conduction dips in the differential tunneling conductance. We explained these features by applying the coherent tunneling model.

• JSTS:Journal of Semiconductor Technology and Science
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• v.4 no.1
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• pp.27-31
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• 2004

Models and simulations of gate tunneling current for thinoxide MOSFETs and Double-Gate SOIs are discussed. A guideline in design of leaky MOS capacitors is proposed and resonant gate tunneling current in DG SOI simulated based on quantum-mechanicalmodels. Gate tunneling current in fully-depleted, double-gate SOI MOSFETs is characterized based on quantum-mechanical principles. The simulated $I_G-V_G$ of double-gate SOI has negative differential resistance like that of the resonant tunnel diodes.

• Journal of Magnetics
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• v.21 no.4
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• pp.491-495
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• 2016

We developed an embedded Object-Oriented Micromagnetic Frame (OOMMF) script schemes for more flexible simulations for complex and dynamic mircomagnetic behaviors. The OOMMF can be called from any kind of softwares by system calls, and we can interact with OOMMF by updating the input files for next step from the output files of the previous step of OOMMF. In our scheme, we set initial inputs for OOMMF simulation first, and run OOMMF for ${\Delta}t$ by system calls from any kind of control programs. After executing the OOMMF during ${\Delta}t$, we can obtain magnetization configuration file, and we adjust input parameters, and call OOMMF again for another ${\Delta}t$ running. We showed one example by using scripting embedded OOMMF scheme, tunneling magneto-resistance dependent switching time. We showed the simulation of tunneling magneto-resistance dependent switching process with non-uniform current density using the proposed framework as an example.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07b
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• pp.811-813
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• 2003

We investigated the electrical properties of self-assembled (4,4'-Di(ethynylphenyl)-2'-nitro-1-thioacetylbenzene), which has been well known as a conducting molecule having possible application to molecular level negative differential resistance(NDR)[1]. Generally, the phenomenon of NDR can be characterized by the decreasing current with the increasing voltage[2]. To deposit the SAM layer onto gold electrode, we transfer the prefabricated nanopores into a 1mM self-assembly molecules in THF solution. Au(111) substrates were prepared by ion beam sputtering method of gold onto the silicon wafer. As a result, we measured the voltage-current properties and confirmed the negative differential resistance properties of self-assembled organic thin film and measured, using Scanning Tunneling Microscopy(STM).

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.10
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• pp.139-143
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• 1996

We report on the static and dynamic characteristics of optically modulated resonant tunneling diode oscillator (RTDO) formed in double-barrier quantum-well structure. Under the illumination of Ti:Sapphire laser, the dc current-voltage (I-V) curves of RTDO shifted towared lower voltages. This characteristic was found to odify the series resistance, negtive differential resistance, capacitance, and the inductance of the RTDO. As a result, the resonant frequency of TRDO centered at 5.302 GHz was found to decrease about 20 MHz under the laser illumination. At a constnat bias voltage, the oscillation frequency decreased linearly as the laser power was increased.

• Journal of the Korean Magnetics Society
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• v.11 no.5
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• pp.202-210
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• 2001

Spin dependent tunneling (SDT) junction devices of Ta/NiFe/Ta/NiFe/FeMn/NiFe/AlOx/CoFe/NiFe/Al with in-situ naturally oxidized Al barrier were fabricated using ion beam deposition and dc sputtering in UHV chamber of 10$^{-9}$ Torr. The maximum tunneling magnetoresistance (TMR) and the product resistance by junction (R$_{j}$ A) are 16-17% and 50-60 $\Omega$${\mu}{\textrm}{m}$$^2$, respectively. The values of TMR and (R$_{j}$ A) with field annealing were slightly increased. The TMR and (R$_{j}$ A) dependence versus the junction area size was observed. These results were explained by using sheet resistance effect of bottom electrode and spin channel effects.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.54 no.2
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• pp.51-54
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• 2005

In this work, the attempt has been made to investigate the morphology of self-assembled dipyridinium dithioacetate on Au(111) substrate by Scanning Tunneling Microscopy(STM). Also, we measured electrical properties(I-V) using Scanning Tunneling Spectroscopy(STS). Sample used in this experiment is dipyridinium dithioacetate, which contains thiol functional group, this structure that can be self-assembled easily to Au(111) substrate. The self-assembly procedure was used for two different concentrations, 0.5 mM/ml and 1 mM/ml. Dilute density of sample by 0.5 mM/ml, 1 mM/ml and observed dipyridinium dithioacetate's image by STM after self-assembled on Au(111) substrate. The structure of STM tip-SAMs-Au(111) substrate has been used measurement for electrical properties(I-V) using STS. The current-voltage(I-V) measurement result, observed negative differential resistance(NDR) properties.