Browsing by Author "Hsu, K. C."

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Device Instability of ReRAM and a Novel Reference Cell Design for Wide Temperature Range Operation
(2017-09-01)
Lin, Y. H.
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Lin, Y. Y.
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Lee, F. M.
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Ho, Y. H.
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Hsu, K. C.
This letter addresses two difficult challenges for transition metal oxide resistive random access memories (ReRAMs)-sensitivity to operation temperature and random fluctuation of resistance value. A careful study of a WOx ReRAM array reveals that these devices are unstable and their read currents fluctuate with time due to random telegraph noise and structure relaxation. Consequently, even after careful programming, the current distribution can broaden with time and tail bit population grows. Furthermore, ReRAM state is sensitive to temperature and a reference cell made of the same device material must be used. Thus, although the broadening of read current distribution may be tolerated by creating a larger RESET/SET memory window, the current fluctuation still makes it impossible to predict the output of the reference cell, leading to array malfunction. This letter investigates the current (resistance) instability in detail and proposes a reference array with a novel trimming method that can stabilize the reference current level. The proposed reference array has very good dc stress reliability as well as wide-range temperature tracking performance from -40 degrees C to 85 degrees C.
Higher kappa Metal-Gate/High-kappa/Ge n-MOSFETs with < 1 nm EOT Using Laser Annealing
(2010)
Chen, W. B.
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Shie, B. S.
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Chin, Albert
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Hsu, K. C.
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Chi, C. C.
High performance metal-gate/high-kappa/Ge n-MOSFETs are reached with low 73 Omega/sq sheet resistance (R(s)), 1.10 ideality factor, 0.95 nm EOT, small 106 mV/dec sub-threshold slope (SS), good 285 cm(2)/Vs high-field (1 MV/cm) mobility and low 37 mV Delta V(t) PBTI (85 degrees C, 1 hr). This is achieved by using 30-ns laser annealing that leads to 57% higher gate capacitance, better n(+)/p junction and 10X better I(ON)/I(OFF).
Improved Capacitance Density and Reliability of High-k Ni/ZrO(2)/TiN MIM Capacitors Using Laser-Annealing Technique
(2010-07-01)
Tsai, C. Y.
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Chiang, K. C.
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Lin, S. H.
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Hsu, K. C.
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Chi, C. C.
We have fabricated high-k Ni/ZrO(2)/TiN metal-insulator-metal capacitors with a very high 52-fF/mu m(2) capacitance density, a low leakage current of 1.6 x 10(-7) A/cm(2), and good ten-year reliability with a small Delta C/C of 1.7% at 2 V. From X-ray diffraction measurements, laser annealing can improve the permittivity of ZrO(2) due to tetragonal-phase formation which in turn helps enhance capacitance density and reliability. Such excellent device integrity is attributed to the combination of enhanced ZrO(2) tetragonal phase by laser annealing, high work-function Ni electrode, and good bottom-interface treatment.
Improved Capacitance Density and Reliability of High-k Ni/ZrO2/TiN MIM Capacitors Using Laser-Annealing Technique
(2010-07-01)
Tsai, C. Y.
;
Chiang, K. C.
;
Lin, S. H.
;
Hsu, K. C.
;
Chi, C. C.
We have fabricated high-k Ni/ZrO2/TiN metal-insulator-metal capacitors with a very high 52-fF/mu m(2) capacitance density, a low leakage current of 1.6 x 10(-7) A/cm(2), and good ten-year reliability with a small Delta C/C of 1.7% at 2 V. From X-ray diffraction measurements, laser annealing can improve the permittivity of ZrO2 due to tetragonal-phase formation which in turn helps enhance capacitance density and reliability. Such excellent device integrity is attributed to the combination of enhanced ZrO2 tetragonal phase by laser annealing, high work-function Ni electrode, and good bottom-interface treatment.
Self-protection multi-ring-architecture fiber sensing system
(2008)
Wang, C. H.
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Yeh, C. H.
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Shih, F. Y.
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Chow, C. W.
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Hsu, K. C.
In this investigation, we propose and experimentally investigate a simply self-restored ring-based fiber Bragg grating (FBG) based sensor system. This proposed multi-ring passive sensing architecture is without any active components in the entire network. In this experiment, the network survivability and capacity for the multi-point sensor systems are also enhanced. Besides, the tunable laser source (TLS) is adopted in central office (CO) for FBG sensing. The survivability of a eight-point FBG sensor is examined and analyzed. Due to the passive sensor network, the cost-effective and intelligent sensing system is entirely centralized by CO. As a result, the experimental results show that the proposed system can assist the reliable FBG sensing network for a large-scale and multi-point architecture.
Surface roughness of sputtered ZnO films
(2006-09-01)
Lin, Y. S.
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Hsu, K. C.
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Huang, Y. M.
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光電工程學系
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Department of Photonics
ZnO films are grown on Si and glass substrates by radio-frequency (RF) magnetron sputtering. The crystalline structures are investigated by x- ray diffraction (XRD). Moreover, the roughness characteristics of the films are examined by atomic force microscopy (AFM) and field-emission scanning electron microscopy (FE-SEM). All films exhibit strong ( 002) preferential orientation. The influence of the RF power and target-to-substrate distance (D-ts) on the properties of ZnO is studied. Under the optimized conditions of the RF power and D-ts, root-mean-square (RMS) surface roughnesses of < 0.8 nm are achieved.