• Title/Summary/Keyword: schottky effect

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Interface Characteristics and Electrical Properties of SiO2 and V2O5 Thin Films Deposited by the Sputtering (스퍼터링 방법으로 증착한 SiO2와 V2O5박막의 전류특성과 계면분석)

  • Li, Xiangjiang;Oh, Teresa
    • Journal of the Semiconductor & Display Technology
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    • v.17 no.4
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    • pp.66-69
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    • 2018
  • This study was researched the electrical properties of semiconductor devices such as ITO, $SiO_2$, $V_2O_5$ thin films. The films of ITO, $SiO_2$, $V_2O_5$ were deposited by the rf magnetron sputtering system with mixed gases of oxygen and argon to generate the plasma. All samples were cleaned before deposition and prepared the metal electrodes to research the current-voltage properties. The electrical characteristics of semiconductors depends on the interface's properties at the junction. There are two kinds of junctions such as ohmic and schottky contacts in the semiconductors. In this study, the ITO thin film was shown the ohmic contact properties as the linear current-voltage curves, and the electrical characteristics of $SiO_2$ and $V_2O_5$ films were shown the non-linear current-voltage curves as the schottky contacts. It was confirmed that the electronic system with schottky contacts enhanced the electronic flow owing to the increment of efficiency and increased the conductivity. The schottky contact was only defined special characteristics at the semiconductor and the interface depletion layer at the junction made the schottky contact which has the effect of leakage current cutoff. Consequently the semiconductor device with shottky contact increased the electronic current flow, in spite of depletion of carriers.

Characterization of Schottky Diodes and Design of Voltage Multiplier for UHF-band Passive RFID Transponder (UHF 대역 수동형 RFID 태그 쇼트키 다이오드 특성 분석 및 전압체배기 설계)

  • Lee, Jong-Wook;Tran, Nham
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.44 no.7 s.361
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    • pp.9-15
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    • 2007
  • In this paper, we present the design of Schottky diodes and voltage multiplier for UHF-band passive RFID applications. The Schottky diodes were fabricated using Titanium (Ti/Al/Ta/Al)-Silicon (n-type) junction in $0.35\;{\mu}m$ CMOS process. The Schottky diode having $4{\times}10{\times}10\;{\mu}m^{2}$ contact area showed a turn-on voltage of about 150 mV for the forward diode current of $20\;{\mu}A$. The breakdown voltage is about -9 V, which provides sufficient peak inverse voltage necessary for the voltage multiplier in the RFID tag chip. The effect of the size of Schottky diode on the turn-on voltage and the input impedance at 900 MHz was investigated using small-signal equivalent model. Also, the effect or qualify factor of the diode on the input voltage to the tag chip is examined, which indicates that high qualify factor Schottky diode is desirable to minimize loss. The fabricated voltage multiplier resulted in a output voltage of more than 1.3 V for the input RF signal of 200mV, which is suitable for long-range RFID applications.

Electrical characteristic and surface morphology of IBE-etched Silicon (이온빔 에칭된 실리콘의 전기적 특성 및 표면 morphology)

  • 지희환;최정수;김도우;구경완;왕진석
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2001.07a
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    • pp.279-282
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    • 2001
  • The IBE(ion beam etching)-induced Schottky barrier variation which depends on various etching history related with ion energy, incident angle and etching time has been investigated using voltage-current, capacitance-voltage characteristics of metal-etched silicon contact and morphology of etched surface were studied using AFM(atomic force microscope). For ion beam etched n-type silicons, Schottky barrier is reduced according to ion beam energy. It can be seen that amount of donor-like positive charge created in the damaged layer is proportional to the ion energy. By contrary, for ion beam etched p-type silicons, the Schottky barrier and specific contact resistance are both increased. Not only etching time but also incident angle of ion beam has an effect on barrier height. Taping-mode AFM analysis shows increased roughness RMS(Root-Mean-Square) and depth distribution due to ion bombardment. Annealing in an N$_2$ ambient for 30 min was found to be effective in improving the diode characteristics of the etched samples and minimum annealing temperatures to recover IBE-induced barrier variation were related to ion beam energy.

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Analysis of Sensing Mechanisms in a Gold-Decorated SWNT Network DNA Biosensor

  • Ahn, Jinhong;Kim, Seok Hyang;Lim, Jaeheung;Ko, Jung Woo;Park, Chan Hyeong;Park, Young June
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.14 no.2
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    • pp.153-162
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    • 2014
  • We show that carbon nanotube sensors with gold particles on the single-walled carbon nanotube (SWNT) network operate as Schottky barrier transistors, in which transistor action occurs primarily by varying the resistance of Au-SWNT junction rather than the channel conductance modulation. Transistor characteristics are calculated for the statistically simplified geometries, and the sensing mechanisms are analyzed by comparing the simulation results of the MOSFET model and Schottky junction model with the experimental data. We demonstrated that the semiconductor MOSFET effect cannot explain the experimental phenomena such as the very low limit of detection (LOD) and the logarithmic dependence of sensitivity to the DNA concentration. By building an asymmetric concentric-electrode model which consists of serially-connected segments of CNTFETs and Schottky diodes, we found that for a proper explanation of the experimental data, the work function shifts should be ~ 0.1 eV for 100 pM DNA concentration and ~ 0.4 eV for $100{\mu}M$.

나노선 구조를 갖는 쇼트키 장벽 MOSFET과 MOSFET의 특성 비교

  • Jeong, Hyo-Eun;Lee, Jae-Hyeon
    • Proceeding of EDISON Challenge
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    • 2013.04a
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    • pp.234-237
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    • 2013
  • 본 논문에서는 실리콘 나노선 구조를 갖는 모스펫 (Metal-Oxide-Semiconductor Field Effect Transistors, MOSFETs)과 쇼트키 장벽 트랜지스터 (Schottky-Barrier(SB) MOSFETs, SB-MOSFETs)의 전기적인 특성을 양자역학적 시뮬레이션 계산을 통해 비교하였다. 쇼트키 장벽 높이 (Schottky Barrier, ${\phi}_{SBH}$)에 따른 SB-MOSFETs의 터널링 특성을 분석하고, 소스/드레인 (S/D) 길이가 변함에 따라 달라지는 S/D 저항을 계산하여, ${\phi}_{SBH}$가 0eV인 SB-MOSFETs의 On과 Off $I_D$ 비율 ($I_{ON}/I_{OFF}$)이 MOSFETs보다 개선될 수 있음을 보였다.

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Electric-field induced si-graphene heterostructure solar cell using top gate

  • Won, Ui-Yeon;Yu, U-Jong
    • Proceedings of the Korean Vacuum Society Conference
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    • 2016.02a
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    • pp.287.2-287.2
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    • 2016
  • Silicon has considerably good characteristics on electron, hole mobility and its price. With 2-D sinlge-layer Graphene/n-Si heterojunction solar cell shows that in one sun condition exhibit power conversion efficiency(PCE) of 10.1%. This photovoltaic effect was achieved by applying gate voltage to the Schottky junction of the heterostructure solar cell. Energy band diagram shows that Schottky barrier between Si and graphene can be adjust by the external electric field. because of the fermi level of the graphene can be changed by external gate voltage, we can control the Schottkky barrier of the heterostructure solar cell. The ratio between generated power of solar cell and consumption electrical power is remarkable. Since we use the graphene as the top gate electrode, most of the sun light can penetrate into the active area.

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A Study on a Palladium-Silicon Garbide Schottky Diode as a Hydrogen Gas Sensor (Pd-SiC 쇼트키 다이오드의 수소 가스 감지 특성)

  • Lee, Joo-Hun;Lee, Young-Hwan;Kim, Chang-Kyo;Cho, Nam-Ihn
    • Proceedings of the KIEE Conference
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    • 1998.11c
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    • pp.858-860
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    • 1998
  • A Pd-SiC Schottky diode for detection of hydrogen gas operating at high temperature was fabricated. Hydrogen-sensing behaviors of Pd-SiC Schottky diode have been analyzed as a function of hydrogen concentration and temperature by I-V and ${\Delta}I$-t methods under steady-state and transient conditions. The effect of hydrogen adsorption on the barrier height was investigated. Analysis of the steady-state kinetics using I-V method confirmed that the atomistic hydrogen adsorption process is responsible for the barrier height change in the diode.

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Electron Transport Mechanisms in Ag Schottky Contacts Fabricated on O-polar and Nonpolar m-plane Bulk ZnO

  • Kim, Hogyoung
    • Transactions on Electrical and Electronic Materials
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    • v.16 no.5
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    • pp.285-289
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    • 2015
  • We prepared silver Schottky contacts to O-polar and nonpolar m-plane bulk ZnO wafers. Then, by considering various transport models, we performed a comparative analysis of the current transport properties of Ag/bulk ZnO Schottky diodes, which were measured at 300, 200, and 100 K. The fitting of the forward bias current-voltage (I-V) characteristics revealed that the tunneling current is dominant as the transport component in both the samples. Compared to thermionic emission (TE), a stronger contribution of tunneling current was observed at low temperature. The reverse bias I-V characteristics were well fitted with the thermionic field emission (TFE) in both the samples. The presence of acceptor-like adsorbates, such as O2 and H2O, modulated the surface conductive state of ZnO, thereby affecting the tunneling effect. The degree of activation/passivation of acceptor-like adsorbates might be different in both the samples owing to their different surface morphologies and surface defects (e.g., oxygen vacancies).

A New Resistance Model for a Schottky Barrier Diode in CMOS Including N-well Thickness Effect

  • Lee, Jaelin;Kim, Suna;Hong, Jong-Phil;Lee, Sang-Gug
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.4
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    • pp.381-386
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    • 2013
  • A new resistance model for a Schottky Barrier Diode (SBD) in CMOS technology is proposed in this paper. The proposed model includes the n-well thickness as a variable to explain the operational behavior of a planar SBD which is firstly introduced in this paper. The model is verified using the simulation methodology ATLAS. For verification of the analyzed model and the ATLAS simulation results, SBD prototypes are fabricated using a $0.13{\mu}m$ CMOS process. It is demonstrated that the model and simulation results are consistent with measurement results of fabricated SBD.

Influences of Trap States at Metal/Semiconductor Interface on Metallic Source/Drain Schottky-Barrier MOSFET

  • Cho, Won-Ju
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.7 no.2
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    • pp.82-87
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    • 2007
  • The electrical properties of metallic junction diodes and metallic source/drain (S/D) Schottky barrier metal-oxide-semiconductor field-effect transistor (SB-MOSFET) were simulated. By using the abrupt metallic junction at the S/D region, the short-channel effects in nano-scaled MOSFET devices can be effectively suppressed. Particularly, the effects of trap states at the metal-silicide/silicon interface of S/D junction were simulated by taking into account the tail distributions and the Gaussian distributions at the silicon band edge and at the silicon midgap, respectively. As a result of device simulation, the reduction of interfacial trap states with Gaussian distribution is more important than that of interfacial trap states with tail distribution for improving the metallic junction diodes and SB-MOSFET. It is that a forming gas annealing after silicide formation significantly improved the electrical properties of metallic junction devices.