<link rel="stylesheet" href="styles.cf390c6bfbe7555f.css">

學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

🏛️國立陽明交通大學機構典藏

Author: search.filters.author.Wu, Yu-ShengHas files: Yes

Search Results

Now showing 1 - 10 of 16
  • Thumbnail Image
    Item type:Item,
    Impact of Surface Orientation on the Sensitivity of FinFETs to Process Variations-An Assessment Based on the Analytical Solution of the Schrodinger Equation
    (2010-12-01)
    Wu, Yu-Sheng
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This paper investigates the impact of surface orientation on V(th) sensitivity to process variations for Si and Ge fin-shaped field-effect transistors (FinFETs) using an analytical solution of the Schrodinger equation. Our theoretical model considers the parabolic potential well due to short-channel effects and, therefore, can be used to assess the quantum-confinement effect in short-channel FinFETs. Our study indicates that, for ultrascaled FinFETs, the importance of channel thickness (t(ch)) variations increases due to the quantum-confinement effect. The Si-(100) and Ge-(111) surfaces show lower V(th) sensitivity to the t(ch) variation as compared with other orientations. On the contrary, the quantum-confinement effect reduces the V(th) sensitivity to the L(eff) variation, and Si-(111) and Ge-(100) surfaces show lower V(th) sensitivity as compared with other orientations. Our study may provide insights for device design and circuit optimization using advanced FinFET technologies.
  • Thumbnail Image
    Item type:Item,
    Impact of Quantum Confinement on Short-Channel Effects for Ultrathin-Body Germanium-on-Insulator MOSFETs
    (2011-01-01)
    Wu, Yu-Sheng
    ;
    Hsieh, Hsin-Yuan
    ;
    Hu, Vita Pi-Ho
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    This letter investigates the impact of quantum confinement (QC) on the short-channel effect (SCE) of ultrathin-body (UTB) and thin-buried-oxide germanium-on-insulator (GeOI) MOSFETs using an analytical solution of Schrodinger equation verified with TCAD simulation. Our study indicates that, although the QC effect increases the threshold voltage (V(th)) roll-off when the channel thickness (T(ch)) is larger than a critical value (T(ch,crit)), it may decrease the V(th) roll-off of GeOI MOSFETs when the T(ch) is smaller than T(ch,crit). Since Ge and Si channels exhibit different degrees of confinement and T(ch,crit), the impact of QC must be considered when one-to-one comparisons between UTB GeOI and Si-on-insulator MOSFETs regarding the SCE are made.
  • Thumbnail Image
    Item type:Item,
    Fabrication and characteristics of a GaN-based microcavity laser with shallow etched mesa
    (2014-06-01)
    Lai, Ying-Yu
    ;
    Chou, Yu-Hsun
    ;
    Wu, Yu-Sheng
    ;
    Lan, Yu-Pin
    ;
    Lu, Tien-Chang
    In this work, we have developed a simple GaN-based microcavity (MC) with an intracavity shallow etched mesa. The textured GaN-based MC incorporated two high-reflectivity dielectric Bragg mirrors and an InGaN/GaN multiple quantum well with a shallow etched mesa as an optical confined structure. Lasing and transverse optical confinement characteristics have been verified by measuring devices with different mesa diameters. A quality factor (Q) of 2600 and a threshold energy of 30 nJ have been observed in a 10-mu m-diameter device. Such a cavity structure could be implanted into electrically pumped GaN vertical-cavity surface-emitting lasers for supporting efficient transverse confinement. (C) 2014 The Japan Society of Applied Physics
  • Thumbnail Image
    Item type:Item,
    Impact of Quantum Confinement on Backgate-Bias Modulated Threshold-Voltage and Subthreshold Characteristics for Ultra-Thin-Body GeOI MOSFETs
    (2012-07-01)
    Yu, Chang-Hung
    ;
    Wu, Yu-Sheng
    ;
    Hu, Vita Pi-Ho
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    This paper investigates the impact of quantum confinement (QC) on the backgate-bias (V-bg) modulated subthreshold and threshold-voltage (V-th) characteristics of ultra-thin-body germanium-on-insulator (UTB GeOI) MOSFETs using an analytical solution of the Schrodinger equation verified with TCAD numerical simulation. Our study indicates that the QC effect reduces the sensitivity of the subthreshold swing to V-bg. In addition, the sensitivity of V-th to V-bg can be enhanced by the QC effect particularly for electrostatically well-behaved UTB MOSFETs with triangular potential well. Aside from that, the sensitivity of V-th roll-off to V-bg is reduced by the QC effect. Since Ge and Si channels exhibit different degrees of QC due to different quantization effective mass, the impact of QC has to be considered when one-to-one comparisons between GeOI and SOI MOSFETs regarding the backgate-bias modulated threshold-voltage and subthreshold characteristics are made. Our study may provide insights for multi-V-th device/circuit designs using advanced UTB GeOI technologies.
  • Thumbnail Image
    Item type:Item,
    Impact of Quantum Confinement on Subthreshold Swing and Electrostatic Integrity of Ultra-Thin-Body GeOI and InGaAs-OI n-MOSFETs
    (2012-03-01)
    Yu, Chang-Hung
    ;
    Wu, Yu-Sheng
    ;
    Hu, Vita Pi-Ho
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    This paper investigates the electrostatic integrity (EI) of ultra-thin-body (UTB) germanium-on-insulator (GeOI) and InGaAs-OI n-MOSFETs considering quantum confinement (QC) using a derived analytical solution of Schrodinger equation verified with TCAD numerical simulation. Although the electron conduction path of the high-mobility channel device can be far from the frontgate interface due to high channel permittivity, our study indicates that the quantum confinement effect can move the carrier centroid toward the frontgate and, therefore, improve the subthreshold swing (SS) of the UTB device. Since InGaAs, Ge, and Si channels exhibit different degrees of quantum confinement due to different quantization effective mass, the impact of quantum confinement has to be considered when one-to-one comparisons among UTB InGaAs-OI, GeOI, and SOI MOSFETs regarding the subthreshold swing and electrostatic integrity are made.
  • Thumbnail Image
    Item type:Item,
    A Closed-Form Quantum "Dark Space" Model for Predicting the Electrostatic Integrity of Germanium MOSFETs With High-k Gate Dielectric
    (2012-03-01)
    Wu, Yu-Sheng
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This paper provides a closed-form model of the "dark space (DS)" for Ge MOSFETs with high-k gate dielectrics. This model shows accurate dependences on barrier height, surface electric field, and quantization effective mass of the channel and gate dielectric. Our model predicts that the surface DS due to quantum confinement decreases with reverse substrate bias and increasing channel doping. Our model can be also used for devices with a steep retrograde doping profile. This physically accurate model will be crucial to the prediction of the subthreshold swing and electrostatic integrity of advanced Ge devices.
  • Thumbnail Image
    Item type:Item,
    Investigation of random dopant fluctuation for multi-gate metal-oxide-semiconductor field-effect transistors using analytical solutions of three-dimensional Poisson's equation
    (2008-04-01)
    Wu, Yu-Sheng
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This paper investigates the random dopant fluctuation of multi-gate metal-oxide-semi conductor field-effect transistors (MOSFETs) using analytical solutions of three-dimensional (3D) Poisson's equation verified with device simulation. Especially, we analyze the impact of aspect ratio on the random dopant fluctuation in multi-gate devices. Our study indicates that with a given total width, lightly doped fin-type FET (FinFET) shows the smallest threshold voltage (V(th)) dispersion because of its smaller Vth sensitivity to the channel doping. For heavily doped devices, quasi-planar shows smaller V(th) dispersion because of its larger volume. The Vth dispersion caused by random dopant fluctuation may still be significant in the lightly doped channel, especially for tri-gate and quasi-planar devices.
  • Thumbnail Image
    Item type:Item,
    Sensitivity of multigate MOSFETs to process variations - An assessment based on analytical solutions of 3-D Poisson's equation
    (2008-05-01)
    Wu, Yu-Sheng
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This paper investigates the sensitivity of multigate MOSFETs to process variations using analytical solutions of 3-D Poisson's equation verified with device simulation. FinFET and Tri-gate with both heavily doped and lightly doped channels have been examined regarding their immunity to process-induced variations and dopant number fluctuation. Our study indicates that lightly doped FinFET has the smallest threshold voltage (V-th) dispersion caused by process variations and dopant number fluctuation. For heavily doped devices, dopant number fluctuation may become the dominant factor in the determination of overall V-th variation. The V-th dispersion of Tri-gate may therefore be smaller than that of FinFET because of its better immunity to dopant number fluctuation.
  • Thumbnail Image
    Item type:Item,
    Comparison of 4T and 6T FinFET SRAM Cells for Subthreshold Operation Considering Variability-A Model-Based Approach
    (2011-03-01)
    Fan, Ming-Long
    ;
    Wu, Yu-Sheng
    ;
    Hu, Vita Pi-Ho
    ;
    Hsieh, Chien-Yu
    ;
    Su, Pin
    This paper investigates the cell stability of recently introduced four-transistor (4T) and conventional six-transistor (6T) fin-shaped field-effect transistor static random access memory (SRAM) cells operating in a subthreshold region using an efficient model-based approach to consider the impact of device variations. Compared with the 6T cell, this paper indicates that 4T SRAM cells exhibit a better nominal READ static noise margin (RSNM) because of the reduced READ disturb. For 4T cells, the nearly ideal values of V(write, 0) and V(write, 1) guarantee the positive nominal WRITE static noise margin (WSNM) for selected cells. For half-selected cells on the selected bit line, a sufficient margin is observed between WRITE time (for selected cells) and WRITE disturb (for half-selected cells). Using the established model-based approach, the variability of subthreshold 6T and 4T SRAM cells is assessed with 1000 samples. Our results indicate that the 4T driverless cell with a larger mu RSNM and a slightly worse sigma RSNM shows a comparable mu/sigma ratio in RSNM with the 6T cell. Furthermore, for a given cell area, 4T SRAM cells using relaxed device dimensions with reduced sigma RSNM can outperform the 6T cell. For WRITE operation, 4T SRAM cells exhibit a superior WSNM, whereas the design margin between WRITE time and WRITE disturb needs to be carefully examined to ensure an adequate margin considering device variability.
  • Thumbnail Image
    Item type:Item,
    Investigation of Electrostatic Integrity for Ultrathin-Body Germanium-On-Nothing MOSFET
    (2011-03-01)
    Hu, Vita Pi-Ho
    ;
    Wu, Yu-Sheng
    ;
    Su, Pin
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This paper examines the electrostatic integrity of ultrathin-body (UTB) germanium-on-nothing (GeON) MOSFET using theoretically calculated subthreshold swing from the analytical solution of Poisson's equation. Our results indicate that UTB GeON MOSFETs with the ratio of channel length (L(g)) to channel thickness (T(ch)) around 4 can show comparable subthreshold swing to that of the silicon-on-nothing counterparts. The impact of buried insulator (BI) thickness (T(BI)) and BI permittivity on the electrostatic integrity of the UTB germanium channel devices are also examined.