Browsing by Author "Chiu, Y. C."

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Analysis of the proximity effect and the interface transparency with perpendicular current in Ni/Nb system
(2009-04-01)
Huang, S. Y.
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Chiu, Y. C.
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Liang, J. J.
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Lin, L. K.
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Tsai, T. C.
We quantitatively study the interface resistance in Ni/Nb multilayers fabricated by sputtering system. For a fixed Ni layer thickness in Ni/Nb/Ni trilayers, the superconducting temperature T(c) decreases with decreasing Nb thickness. By analyzing the data with the proximity effect, the critical thickness below which superconductivity vanished was deduced. From current perpendicular to plane (CPP) measurement interpreted with a one-band series-resistor model, we obtained the CPP resistivities of Nb and Ni and the unit area resistances of 4.2 +/- 0.2 and 1.5 +/- 0.4 f Omega m(2) for superconducting and normal Ni/ Nb interfaces. The transparency parameter is directly calculated in terms of interface resistance. (C) 2009 American Institute of Physics. [DOI: 10.1063/1.3073657]
Channel Modification Engineering by Plasma Processing in Tin-Oxide Thin Film Transistor: Experimental Results and First-Principles Calculation
(2017-01-01)
Chiu, Y. C.
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Chen, P. C.
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Chang, S. L.
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Zheng, Z. W.
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Cheng, C. H.
In this paper, we investigated the effects of oxygen plasma treatment on tin oxide (SnOx) thin film transistors (TFTs). By using oxygen plasma treatment on SnOx active channel layer, excess oxygen was incorporated to the channel layer and converted oxygen-deficient SnOx to oxygen-rich SnO2-x, which in turn causes the device operation from p-type to n-type. Tuning the different exposure time of oxygen plasma, the optimal TFT device exhibits n-type properties with an on/off current ratio of 2.6 x 10(4), a very high field-effect mobility of 89 cm(2) V-1 s(-1), and a threshold voltage of -0.95 V. Furthermore, the effects of oxygen plasma treatment on band structure, density of states and electron density difference of the SnOx channel layer were performed by the first-principles calculation using density functional theory. The results show that the oxygen plasma treatment approach has high potential for high-performance TFT applications. (C) 2017 The Electrochemical Society. All rights reserved.
Electrical instability of InGaZnO thin-film transistors with and without titanium sub-oxide layer under light illumination
(2017-03-01)
Chiu, Y. C.
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Zheng, Z. W.
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Cheng, C. H.
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Chen, P. C.
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Yen, S. S.
The electrical instability behaviors of amorphous indium-gallium-zinc oxide thin-film transistors with and without titanium sub-oxide passivation layer were investigated under light illumination in this study. For the unpassivated IGZO TFT device, in contrast with the dark case, a noticeable increase of the sub-threshold swing was observed when under the illumination environment, which can be attributed to the generation of ionized oxygen vacancies within the alpha-IGZO active layer by high energy photons. For the passivated TFT device, the much smaller SS of similar to 70 mV/dec and high device mobility of >100 cm(2)/Vs at a drive voltage of 3 V with negligible degradation under light illumination are achieved due to the passivation effect of n-type titanium sub-oxide semiconductor, which may create potential application for high-performance display.
High Mobility InGaZnO Thin Film Transistor Using Narrow-Bandgap Titanium-Oxide Semiconductor as Channel Capping Layer
(2014-01-01)
Hsu, H. H.
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Chiou, P.
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Chiu, Y. C.
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Yen, S. S.
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Chang, C. Y.
Investigation of Electrical Characteristics on 25-nm InGaAs Channel FinFET Using InAlAs Back Barrier and Al2O3 Gate Dielectric
(2017-01-01)
Lin, M. H.
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Lin, Y. C.
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Lin, Y. S.
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Sun, W. J.
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Chen, S. H.
We investigated an N-type III-V FinFET with a 25-nm In0.53Ga0.47As channel and a 300-nm In0.52Al0.48As barrier layer on an InP substrate. The In0.52Al0.48As barrier layer is used to suppress leakage current from the InP substrate and the 10-nm Al2O3 film deposited by atomic layer deposition (ALD) can be a robust gate dielectric to mitigate interface traps. The on to off current ratio is approximately three orders of magnitude, the subthreshold swing (SS) is 350 mV/dec, and the maximum driving current density is 130 mu A/mu m at V-G = 1.5 V for InGaAs FinFET with a fin width of 40 nm and gate length of 200 nm. (c) 2017 The Electrochemical Society. All rights reserved.
The Impact of the Shallow-Trench Isolation Effect on Flicker Noise of Source Follower MOSFETs in a CMOS Image Sensor
(2018-06-01)
Fan, C. C.
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Chiu, Y. C.
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Liu, C.
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Lai, W. W.
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Cheng, C. H.
The flicker noise of source follower transistors is the dominant noise source in image sensors. This paper reports a systematic study of the shallow trench isolation effect in transistors with different sizes under high temperature conditions that correspond to the quantity of empty defect sites. The effects of shallow trench isolation sidewall defects on flicker noise characteristics are investigated. In addition, the low-frequency noise and subthreshold swing degrade simultaneously in accordance to the device gate width scaling. Both serious subthreshold leakage and considerable noise can be attributed to the high trap density near the STI edge. Consequently, we propose a coincidental relationship between the noise level and the subthreshold characteristic; its trend is identical to the experiments and simulation results.
Ultra-Low Switching Power RRAM Using Hopping Conduction Mechanism
(2012)
Chin, Albert
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Cheng, C. H.
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Chiu, Y. C.
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Zheng, Z. W.
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Liu, M.
Very low 0.4 pJ switching energy, fast 50 ns switching time, large > 10(5) retention window at 85 degrees C, and 10(6) cycling endurance were achieved in Ni/GeOx/SrTiOy/TaN RRAM. This RRAM device has negative temperature coefficient (TC) and ruled by bulk hopping conduction mechanism that lead to potentially better distribution. This is in sharp contrast to the positive TC and randomly distributed metallic filament RRAM. Such low switching energy is necessary for large-array NAND memory application, a unique merit of this RRAM device.