• Title/Summary/Keyword: device structure

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Feasibility Study of Non-volatile Memory Device Structure for Nanometer MOSFET (나노미터 MOSFET비휘발성 메모리 소자 구조의 탐색)

  • Jeong, Ju Young
    • Journal of the Semiconductor & Display Technology
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    • v.14 no.2
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    • pp.41-45
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    • 2015
  • From 20nm technology node, the finFET has become standard device for ULSI's. However, the finFET process made stacking gate non-volatile memory obsolete. Some reported capacitor-less DRAM structure by utilizing the FBE. We present possible non-volatile memory device structure similar to the dual gate MOSFET. One of the gates is left floating. Since body of the finFET is only 40nm thick, control gate bias can make electron tunneling through the floating gate oxide which sits across the body. For programming, gate is biased to accumulation mode with few volts. Simulation results show that the programming electron current flows at the interface between floating gate oxide and the body. It also shows that the magnitude of the programming current can be easily controlled by the drain voltage. Injected electrons at the floating gate act similar to the body bias which changes the threshold voltage of the device.

A Novel LC Device Associated with Optically Compensated Splay Structure (광학적 자기 보상 스플레이 구조를 갖는 새로운 액정 소자)

  • 김승재;이종문;이승희
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.5
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    • pp.536-540
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    • 2004
  • A novel nematic liquid crystal (LC) cell with splay structure exhibiting wide viewing angle, fast response time and high transmittance at the same time has been developed. With rubbed homeotropic alignment in parallel directions, the device shows bend alignment in the absence of vertical electric field. However, with applied high voltage in a pulse form, the LC shows a optically compensated splay (OCS) orientation such that the mid-director is parallel to a substrate and at both surfaces the LCs are aligned vertically in parallel direction. In the device, the birefringence of the cell becomes tunable with applying voltage, i.e., the amount of light passed through the cell can be controlled by controlling the orientation of the LC. Since the OCS cell has a self-compensation structure such that the LC has a mirror symmetry along the mid-director, the device shows a wide viewing angle with only a single domain and a fast response time.

Optimization Study on the Epitaxial Structure for 100nm-Gate MHEMTs with InAlAs/InGaAs/GaAs Heterostructure (InAlAs/InGaAs/GaAs 100 nm-게이트 MHEMT 소자의 에피 구조 최적화 설계에 관한 연구)

  • Son, Myung-Sik
    • Journal of the Semiconductor & Display Technology
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    • v.10 no.4
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    • pp.107-112
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    • 2011
  • This paper is for improving the RF frequency performance of a fabricated 100nm ${\Gamma}$-gate MHEMT, scaling down vertically for the epitaxy-structure layers of the device. Hydrodynamic simulation parameters are calibrated for the fabricated MHEMT with the modulation-doped $In_{0.52}Al_{0.48}As/In_{0.53}Ga_{0.47}$As heterostructure grown on the GaAs substrate. With these calibrated parameters, simulations for the vertically-scaled epitaxial layers of the device are performed and analyzed for DC/RF characteristics, including the quantization effect due to the thickness reduction of InGaAs channel layer. A newly designed epitaxy-structure device shows higher extrinsic transconductance, $g_m$ of 1.556 S/mm, and higher frequency performance, $f_T$ of 222.5 GHz and $f_{max}$ of 849.6 GHz.

The effect of RF electric fields from an atmospheric micro-plasma needle device on the death of cells (침형 상압 마이크로 플라즈마 장치에서 발생하는 전기장이 세포 사멸에 미치는 효과)

  • Yoon, Hyun-Jin;Shon, Chae-Hwa;Kim, Gyoo-Cheon;Lee, Hae-June
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.12
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    • pp.2249-2254
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    • 2008
  • A non-thermal micron size plasma needle is applicable for medical treatment because it includes radicals, charged particles, ultraviolet emission, and strong electric fields. The electric fields around the plasma needle device driven by a radio frequency wave are investigated in order to calculate the power delivered to the cell. A commercial multi-physics code, CFD-ACE, was utilized for the calculation of electric fields for the optimization of the needle structure. The electric field and energy absorption profiles are presented with the variation of the device structure and the distance between the needle and tissues. The living tissues effectively absorb the radio frequency power from the plasma needle device with the covered pyrex structure.

Development of Gate Structure in Junctionless Double Gate Field Effect Transistors (이중게이트 구조의 Junctionless FET 의 성능 개선에 대한 연구)

  • Cho, Il Hwan;Seo, Dongsun
    • Journal of IKEEE
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    • v.19 no.4
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    • pp.514-519
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    • 2015
  • We propose the multiple gate structure of double gate junctionless metal oxide silicon field oxide transistor (JL MOSFET) for device optimization. Since different workfunction within multiple metal gates, electric potential nearby source and drain region is modulated in accordance with metal gate length. On current, off current and threshold voltage are influenced with gate structure and make possible to meet some device specification. Through the device simulation work, performance optimization of double gate JL MOSFETs are introduced and investigated.

High brightness property of Power Electroluminescent Device using ZnS:Cu (ZnS:Cu를 이용한 후막 전계발광소자의 고휘도 특성)

  • Lee, Jong-Chan;Park, Dae-Hui
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.48 no.5
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    • pp.349-353
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    • 1999
  • In this paper, to fabricate the AC power electroluminescent device (PELD) with high brightness, new structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material structure that constructed single emissive layer between electrodes was proposed. Dielectric and phosphor material were BaTiO3 and ZnS:Cu respectively. Fabricated AC power EL devices were estimated by optical and electrical properties of EL spectrum, brightness, CIE coordinate system, transferred charge density and EL emission wave in time domain. With above results, we found that brightness of newly proposed AC powder EL power EL device was 2754 cd/m2 at 100V, 400 Hz and compared with conventional device structure.

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Estimation of Equivalent Viscous Damping of Structure with Base Isolation Devices (면진장치를 가지는 구조물의 등가점성감쇠비 산정)

  • 김태호;이동근
    • Proceedings of the Earthquake Engineering Society of Korea Conference
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    • 2002.03a
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    • pp.359-366
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    • 2002
  • Direct Integration method(D.I) and Mode Superposition method(M.S) are used widely in dynamic analysis method for structure with isolation devices. D.I is used firstly because it is consider to nonlinearity of isolation device. M.S is applied in elastic region, but it is difficult to apply M.S because coincidence with othogonality condition in the case of adding the damping of isolation device. In this study, the method for calculation of damping ratio of isolated structure is proposed, and proposed method is verified with analysis for example structure.

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Generation of valley polarized current in graphene using quantum adiabatic pumping

  • Wang, Jing;Chan, K.S.
    • Advances in nano research
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    • v.3 no.1
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    • pp.39-47
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    • 2015
  • We study a device structure which can be used to generate pure valley current and valley polarized current using quantum adiabatic pumping. The design of the structure allows the flexibility of changing the structure from one for pure valley current generation to one for valley polarized current generation by changing the applied electric potentials through changing the symmetry of the structure. The device is useful for the development of valleytronic devices.

Impedance Characteristics of Fluorescent OLED with Device Structure (소자 구조에 따른 형광 OLED의 Impedance 특성)

  • Kong, Do-Hoon;Ju, Sung-Hoo
    • Korean Journal of Materials Research
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    • v.28 no.1
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    • pp.18-23
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    • 2018
  • To study the impedance characteristics of a fluorescent OLED according to the device structure, we fabricated Device 1 using ITO / NPB / $Alq_3$ / Liq / Al, Device 2 using ITO / 2-TNATA / NPB / $Alq_3$ / Liq / Al, and Device 3 using ITO / 2-TNATA / NPB / SH-1:BD / $Alq_3$ / Liq / Al. The current density and luminance decreased with an increasing number of layers of the organic thin films in the order of Device 1, 2, 3, whereas the current efficiency increased. From the Cole-Cole plot at a driving voltage of 6 V, the maximum impedance values of Devices 1, 2, and 3 were respectively 51, 108, and $160{\Omega}$ just after device fabrication. An increase in the impedance maximum value is a phenomenon caused by the charge mobility and the resistance between interfaces. With the elapse of time after the device fabrication, the shape of the Cole-Cole plot changed to a form similar to 0 or a lower voltage due to the degradation of the device. As a result, we were able to see that an impedance change in an OLED reflects the characteristics of the degradation and the layer.

Barrier Layers and Pulsed Laser Annealing Effects on TFEL Device with Cu and Ag co-doped SrS blue Phosphor Layer

  • Nam, Tae-Sung;Liew, Shan-Chun;Koutsogeorgis, Demosthenes C;Cranton, Wayne M
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.910-913
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    • 2003
  • In order to enhance performance, stability, and brightness of inorganic blue-light emitting EL device, barrier layer structure and pulsed laser annealing(PLA) treatment were introduced. The barrier layer structure was utilized for improving brightness of the device and instead of thermal annealing, pulsed laser annealing process was used. From this study, optimum barrier layer thickness and number of pulsed laser irradiation are established.

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