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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.

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Now showing 1 - 10 of 17
  • Item type:Item,
    Evaluation of Monolithic 3-D Logic Circuits and 6T SRAMs With InGaAs-n/Ge-p Ultra-Thin-Body MOSFETs
    (2016-03-01)
    Yu, Kuan-Chin
    ;
    Fan, Ming-Long
    ;
    Su, Pin
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    This paper evaluates monolithic 3-D logic circuits and 6T SRAMs composed of InGaAs-n/Ge-p ultra-thin-body MOSFETs while considering interlayer coupling through TCAD mixed-mode model. This paper indicates that monolithic 3-D InGaAs/Ge logic circuits provide equal leakage and better delay performance compared with planar 2-D structure through optimized 3-D layout. The monolithic 3-D InGaAs/Ge 6T SRAMs can simultaneously improve the cell stability and performance through optimized 3-D layout. We suggest two 3-D SRAM layout designs for high performance and low power applications, respectively. Moreover, with optimized 3-D layout designs, InGaAs/Ge logic circuits exhibit larger delay improvement, and the 6T SRAMs exhibit larger read access time and time-to-write improvement compared with Si counterparts.
  • Item type:Item,
    SRAM Write-Ability Improvement With Transient Negative Bit-Line Voltage
    (2011-01-01)
    Mukhopadhyay, Saibal
    ;
    Rao, Rahul M.
    ;
    Kim, Jae-Joon
    ;
    Chuang, Ching-Te
    ;
    交大名義發表
    Increasing variations in device parameters significantly degrades the write-ability of SRAM cells in deep sub-100 nm CMOS technology. In this paper, a transient negative bit-line voltage technique is presented to improve write-ability of SRAM cell. Capacitive coupling is used to generate a transient negative voltage at the low-going bit-line during Write operation without using any on-chip or off-chip negative voltage source. Statistical simulations in a 45-nm PD/SOI technology show a 10(3) X reduction in the Write-failure probability with the proposed method.
  • Item type:Item,
    Impact of Random Variations on Cell Stability and Write-Ability of Low-Voltage SRAMs Using Monolayer and Bilayer Transition Metal Dichalcogenide (TMD) MOSFETs
    (2016-07)
    Yu, Chang-Hung
    ;
    Su, Pin
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This letter evaluates and analyzes the impacts of random variations on cell stability and write-ability of low-voltage SRAMs using monolayer and bilayer transition metal dichalcogenide (TMD) devices based on ITRS 2028 (5.9 nm) node with the aid of atomistic TCAD mixed-mode simulations. Our study indicates that, for 6T SRAM, the monolayer/bilayer TMD devices may fail to provide the 6 sigma yield requirement for read static noise margin (RSNM) due to severe metal-gate work function variation in spite of their excellent electrostatics, and hence circuit techniques, such as bootstrapped dynamic power rails or the standard 8T cell, are needed. Besides, R-SD as a major concern of TMDs should be less of an issue for near-/sub-threshold SRAMs for ultra low-power applications. For the standard 8T cell structure, the RSNMs of both monolayer and bilayer 8T SRAMs improve significantly, and the bilayer 8T SRAM exhibits better write static noise margin (WSNM). In addition, write-assist techniques (including negative bit-line, boosted word-line, and lower cell supply) for improving WSNM are examined and shown to be more effective for monolayer 8T SRAMs than the bilayer counterparts.
  • Item type:Item,
    Impacts of NBTI and PBTI on Ultra-Thin-Body GeOI 6T SRAM Cells
    (2015)
    Hu, Vita Pi-Ho
    ;
    Fan, Ming-Long
    ;
    Su, Pin
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    This paper investigates the impacts of Negative and Positive Bias Temperature Instabilities (NBTI and PBTI) on the stability and performance of Ultra-Thin-Body (UTB) GeOI 6T SRAM cells compared with the SOI counterparts. Worst case stress scenarios for Read and Write operations are analyzed. For UTB GeOI SRAM cells, PBTI dominates the degradations in RSNM, HSNM, cell Read access time, and Time-to-Write, while for UTB SOI SRAM cells, NBTI dominates the degradations in RSNM, HSNM, and Time-to-Write. WSNM only slightly degrades due to NBTI/PBTI. Threshold voltage design and Word-Line Under-Drive (WLUD) Read-Assist techniques are analyzed to compensate the stability degradation due to NBTI/PBTI for UTB GeOI SRAM cells. Compared with the nominal UTB GeOI SRAM cells with low Vth design, UTB GeOI SRAM cells with high Vth design suffer less NBTI/PBTI degradations and exhibit significant improvement in RSNM and HSNM, and comparable performance compared with the nominal UTB SOI SRAM cells.
  • Item type:Item,
    Evaluation of Read-and Write-Assist Circuits for GeOI FinFET 6T SRAM Cells
    (2014-01-01)
    Hu, Vita Pi-Ho
    ;
    Fan, Ming-Long
    ;
    Su, Pin
    ;
    Chuang, Ching-Te
    ;
    電機工程學系
    This paper evaluates the impacts of Read- and Write-Assist circuits on the GeOI FinFET 6T SRAM cells compared with the SOI counterparts. The Word-Line Under-Drive (WLUD) Read-Assist is more efficient to improve the Read Static Noise Margin (RSNM) and Read VMIN of FNSP GeOI FinFET SRAM cells compared with the SOI counterparts. GeOI FinFET SRAM cells with WLUD show smaller cell Read accesstime compared with the SOI FinFET SRAM cells at both 25 degrees C and 125 degrees C. Negative Bit-Line (NBL) Write-Assist is more efficient to improve the Write Static Noise Margin (WSNM) than VCS (cell supply) lowering for both GeOI and SOI FinFET SRAM cells. NBL Write-Assist shows larger WSNM improvement for GeOI FinFET SRAM cells than the SOI counterparts at 125 degrees C.
  • Item type:Item,
    Analysis of GeOI FinFET 6T SRAM Cells With Variation-Tolerant WLUD Read-Assist and TVC Write-Assist
    (2015-06-01)
    Hu, Vita Pi-Ho
    ;
    Fan, Ming-Long
    ;
    Su, Pin
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    This paper analyzes the impacts of read-assist and write-assist circuits on GeOI FinFET 6T SRAM cells considering intrinsic random variations, process corner, and temperature variation. The word-line under-drive (WLUD) read-assist is more efficient to improve the read static noise margin and read V-MIN of fast-N slow-P corner GeOI FinFET SRAM cells compared with the Silicon-On-Insulator (SOI) counterparts. GeOI FinFET SRAM cells with WLUD show less cell read access-time degradation compared with the SOI counterparts at both 25 degrees C and 125 degrees C. With transient voltage collapse (TVC) write-assist, the write-ability and variation tolerance of GeOI and SOI FinFET SRAM cells are improved. The temperature dependence of data retention time is different between the GeOI and SOI FinFET SRAM cells. The maximum TVC write-assist pulsewidth constrained by the data retention failure is smaller in GeOI FinFET SRAMs at 25 degrees C and becomes comparable at 125 degrees C compared with the SOI FinFET SRAMs.
  • Item type:Item,
    Impacts of gate-oxide breakdown on power-gated SRAM
    (2011-01-01)
    Yang, Hao-I
    ;
    Hwang, Wei
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    ;
    Department of Electronics Engineering and Institute of Electronics
    This paper presents a detailed analysis on the impacts of various gate-oxide breakdown (BD) paths in column-based header- and footer-gated SRAMs. It is shown that with gate-oxide BD, the read static noise margin (RSNM) and write margin (WM) degrade in general. Pass-transistor gate-oxide BD between WL and BL is shown to degrade read/write margin and performance, and to affect other healthy cells along the same column as well. The effects of gate-to-source BD of cell transistors are shown to confine to the individual cells, while multiple cells suffering cell transistor drain-to-drain BD in a column could cumulatively affect VVDD (header structure) or VVSS (footer structure), thus influencing other cells in the same column. In particular, we show that the gate-oxide BD of the power-switches has severe and even detrimental effects on the margin, stability, and performance of the SRAM array. Several techniques to mitigate the power-switch gate-oxide BD have been evaluated, including adding a gate series resistance to the power-switch, dual threshold voltage power-switch, thick gate-oxide power-switch, and dual gate-oxide thickness (dual-T(OX)) power-switch. It is shown that the dual-Tox power-switch improves the time-to-dielectric-breakdown (7(BD)) of the power-switch while maintaining the performance without side effect. (C) 2010 Elsevier Ltd. All rights reserved.
  • Item type:Item,
    40 nm Bit-Interleaving 12T Subthreshold SRAM With Data-Aware Write-Assist
    (2014-09-01)
    Chiu, Yi-Wei
    ;
    Hu, Yu-Hao
    ;
    Tu, Ming-Hsien
    ;
    Zhao, Jun-Kai
    ;
    Chu, Yuan-Hua
    This paper presents a new bit-interleaving 12T sub-threshold SRAM cell with Data-Aware Power-Cutoff (DAPC) Write-assist to improve the Write-ability to mitigate increased device variations at low supply voltage under deep sub-100 nm processes. The disturb-free feature facilitates the bit-interleaving architecture that can reduce multiple-bit errors in a single word and enhance soft error immunity by employing error checking and correction (ECC) techniques. The proposed 12T SRAM cell is demonstrated by a 4 kb SRAM macro implemented in 40 nm general purpose (40GP) CMOS technology. The test chip operates from typical V-DD to 350 mV (similar to 100 mV lower than the threshold voltage) with V-DDMIN limited by Read operation. Data can be written successfully for V-DD down to 300 mV. The measured maximum operation frequency is 11.5 MHz with total power consumption of 22 mu W at 350 mV, 25 degrees C.
  • Item type:Item,
    Impacts of NBTI/PBTI on Timing Control Circuits and Degradation Tolerant Design in Nanoscale CMOS SRAM
    (2011-06-01)
    Yang, Hao-I.
    ;
    Yang, Shyh-Chyi
    ;
    Hwang, Wei
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    Negative-bias temperature instability (NBTI) and positive-bias temperature instability (PBTI) weaken PFET and NFET over the lifetime of usage, leading to performance and reliability degradation of nanoscale CMOS SRAM. In addition, most of the state-of-the-art SRAM designs employ replica timing control circuit to mitigate the effects of leakage and process variation, optimize the performance, and reduce power consumption. NBTI and PBTI also degrade the timing control circuits and may render them ineffective. In this paper, we provide comprehensive analyses on the impacts of NBTI and PBTI on a two-port 8T SRAM design, including the stability and Write margin of the cell, Read/Write access paths, and replica timing control circuits. We show, for the first time, that because the Read/Write replica timing control circuits are activated in every Read/Write cycle, they exhibit distinctively different degradation behavior from the normal array access paths, resulting in degradation of timing control and performance. We also discuss degradation tolerant design techniques to mitigate the performance and reliability degradation induced by NBTI/PBTI.
  • Item type:Item,
    Device Design and Analysis of Logic Circuits and SRAMs for Germanium FinFETs on SOI and Bulk Substrates
    (2013)
    Hu, Vita Pi-Ho
    ;
    Fan, Ming-Long
    ;
    Su, Pin
    ;
    Chuang, Ching-Te
    ;
    電子工程學系及電子研究所
    A comparative analysis of Germanium-on-Insulator FinFET (GeOl FinFET) and Germanium on bulk substrate FinFET (Ge bulk FinFET) at device and circuit level with respect to Si counterparts is presented. GeOI FinFET shows larger leakage current than Ge bulk FinFET due to the parasitic bipolar effect triggered by the band-to-band tunneling (BTBT) leakage. The effectiveness of different dual-Vt technology options including increasing channel doping, increasing gate length and drain-side underlap for leakage reduction is analyzed for GeOl and Ge bulk FinFET circuits and SRAMs. An optimum asymmetrie underlap design in SRAM using asymmetrie underlap pull-up and access transistors (PUAX-asym) is proposed. GeOl and Ge bulk FinFETs with asymmetrie underlap design show significant improvement in leakage-delay performance and stability in logic circuits and SRAM cells.