Browsing by Author "Chiou, Bi-Shiou"

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Characteristics of low-temperature pulse-laser-deposited (Pb,Sr)TiO3 films in metal/ferroelectric/silicon structure
(2007-01-07)
Wang, Jyh-Liang
;
Lai, Yi-Sheng
;
Lee, Trent Gwo-Yann
;
Chiou, Bi-Shiou
;
Tsai, Chun-Chien
In this study, pulsed- laser deposited ( Pb, Sr) TiO3 ( PSrT) films on p- type Si were studied at low substrate temperatures ranging from 300 to 450 degrees C for metal/ ferroelectric/ semiconductor applications. The substrate temperature strongly enhances film crystallinity without significant inter- diffusion at the PSrT/ Si interface and affects the electrical properties. As the substrate temperature increases, the films have smaller leakage currents, fewer trap states at the electrode interfaces, clockwise capacitance versus applied field hysteresis loops and larger memory windows correlated with superior crystallinity. Conversely, 300 degrees C- deposited films exhibit a small and counterclockwise loop with a positive shift of the flatband voltage, attributed to more negative trap charges within the films. However, the high substrate temperature ( 450 degrees C) may produce serious Pb - O volatilization, incurring more defects and leakage degradation. The analyses of fixed charge density and flatband voltage shift reveal the trap status and agree well with the leakage characteristic. An electron band model of the Pt/ PSrT/ Si electronic structure is proposed to explain the electrical behaviour. The excellent fatigue endurance with a small variation of memory windows (< 11%) after 1010 switching is also demonstrated.
Cost-effective optoelectronic packages using powder metallurgy
(2006-09-01)
Lin, Chun-Ting
;
Chiou, Bi-Shiou
;
Chi, Sien
;
電子工程學系及電子研究所
;
光電工程學系
In this paper, we propose powder metallurgy for optoelectronic packages in order to reduce the cost of laser packages. Conventional die compaction (DC) and metal injection molding (MIM) are used for the shaping of powder metallurgy. The distinguishing types of inherent porosity in DC and MIM steels have their respective effects on the defect mechanisms of laser welding joints. For DC steel with 85% relative density and continuous porosity, the rising gas pressure pushes the molten metal out of the welding regions, resulting in weak and unstable welding joints. For MINI steel with more than 95% relative density, the laser power dominates the defect mechanisms, and the defect-free welding joints with optical spot size of 400 mu m can be attained by using laser power of less than 1.0 M Although elimination of inherent porosity in MIM steel under optimum welding condition can give rise to additional postwelding-shift (PWS), it is still controlled to less than 2 mu m, resulting in optical coupling loss of less than 15%. The advantage of applicability of the MIM method to several materials makes it possible to employ SS316L, Kovar, and Invar, which have the characteristic of better property for laser welding but difficult machining, as the metal housing in low-cost lightwave communication system. Thus, using MIM Invar with low coefficient of thermal expansion can minimize the tracking error, which is an important issue for bidirectional and triple-directional optoelectronic packages. The reliability data demonstrate that the laser modules using MIM steel as construction housing are stable and reliable.
Dependence of ferroelectric characteristics on the deposition temperature of (Pb,Sr)TiO3 films
(2007-10-01)
Wang, Jyh-Liang
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Lai, Yi-Sheng
;
Shye, Der-Chi
;
Chou, Chen-Chia
;
Chiou, Bi-Shiou
The pulsed laser deposition (PLD) of (Pb,Sr)TiO3 (PSrT) films on Pt/SiO2/Si at low substrate temperatures (T-s, ranging from 300 to 450 degrees C, has been investigated. The PLD PSrT films prepared at low Ts exhibit ferroelectric proper-ties, good crystallinity, and no significant interdiffusion between the PSrT film and the Pt bottom electrode. The conduction mechanism is identified as Schottky emission at low electric fields and as Poole-Frenkel emission at high electric fields. PSrT films grown at appropriate T, yield fewer interface states and fewer trapping states, leading to a smaller leakage current. The enhanced (100) preferred orientation of PSrT films deposited at T-s= 350-400 degrees C exhibits optimum ferroelectricity. In addition, the dielectric constant and ferroelectricity are associated with the preferred orientation. This shows that the electrical characteristics strongly rely on the preferred orientation and trapping states, which could be controlled by varying the substrate temperature (T, <= 450 degrees C during PLD.
Dielectric anisotropy in the integration of Cu-SiLK (TM) system
(2008-01-01)
Tseng, Hal-Sin
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Chiou, Bi-Shiou
;
Wu, Wen-Fa
;
Ho, Chia-Cheng
;
電子工程學系及電子研究所
As device density and performance continue to improve, low dielectric constant (k) materials are needed for interlevel dielectric (ILD) applications. The dielectric anisotropy of polymers with low k is an important property to consider for developing ILD. This is on-going research on the integration aspects of Cu-SiLK(TM) system. In this study, the dielectric anisotropy of SiLK polymer was evaluated with two test structures: the metal-insulator-metal (MIM) parallel capacitor structure for the out-of-phase dielectric constant (k(perpendicular to)) and comb-and-serpentine interdigitated structure for the in-plane dielectric constant (k(parallel to)). A k(perpendicular to) of 2.65, a k(parallel to) of 2.75, and a dielectric anisotropy of 3.77% were obtained for SiLK. However, SiLK exhibits larger leakage current as compared to amorphous SiO2 films. The reliability issue on the integration of Cu-SiLK is discussed. (C) 2007 Elsevier B.V. All rights reserved.
Effect of plasma treatment on the microstructure and electrical properties of MIM capacitors with PECVD silicon oxide and silicon nitride
(2007-02-01)
Ho, Chia-Cheng
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Chiou, Bi-Shiou
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
;
Department of Electronics Engineering and Institute of Electronics
Metal-insulator-metal (MIM) capacitors with plasma enhanced chemical vapor deposited (PECVD) nitride exhibit trap-induced dispersive behavior and electrical hysteresis, which lead to degradation in capacitor linearity at low frequencies. The dominant defect was suggested to be silicon dangling bonds originated from nitrogen deficiency. Previous methods to eliminate the dispersive behavior and electrical hysteresis include use of oxide-nitride-oxide (ONO) stacks and/or plasma pre-treatment of silicon substrate before nitride deposition [Van Huylenbroeck S, Decoutere S, Venegas R, Jenei S, Winderickx G (2002) IEEE Electron Device Lett 23:191; Lau WS (1990) Jpn J Appl Phys 29:L690]. In this study, the plasma post-treatment method was employed; MIM capacitors with PECVD oxide and nitride were treated with N2O and SiH4/NH3 plasma, respectively, after deposition of the dielectric layer. No apparent change in film microstructure is observed after plasma treatment. Plasma post-treatment is effective in eliminating the electrical hysteresis shift of the nitride capacitors. Fourier transform infrared (FTIR) absorption spectra suggest an increase of the Si-H bond after SiH4/NH3 plasma bombardment of the nitride films. Auger depth profiling indicates a slight increase of nitrogen to silicon ratio after plasma treatment. The increase of the Si-H bonds as well as the raise of nitrogen to silicon ratio are two possible causes for the elimination of the hysteresis shift of the plasma-treated nitride capacitors. The time dependent dielectric breakdown testing indicates a decrease in both the leakage current and the lifetime of the MIM capacitors treated with plasma. Possible dielectric degradation mechanism is explored.
Effect of size and plasma treatment and the application of Weibull distribution on the breakdown of PECVD SiNx MIM capacitors
(2008-01-01)
Ho, Chia-Cheng
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Chiou, Bi-Shiou
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
;
Department of Electronics Engineering and Institute of Electronics
The dielectric breakdown field is one of the important concerns for device reliability. The breakdown of dielectric is originated at a fatal flaw that grows to cause failure and can be explained by the weakest-link theory. In this study, metal-insulator-metal (MIM) capacitors with plasma enhanced chemical vapor deposited (PECVD) SiNx are prepared. Ammonia (NH3) plasmas are applied after the deposition of the dielectric SiNx. The Weibull distribution function, which is based on the weakest-link theory, is employed to analyze the effect of the electrode area as well as the plasma treatment on the breakdown of the MIM capacitors. The time dependent dielectric breakdown testing indicates a decrease in both the leakage current and the lifetime of the MIM capacitors treated with plasma. Possible dielectric degradation mechanisms are explored. (C) 2007 Elsevier B.V. All rights reserved.
Effect of Top Electrode Materials on the Nonvolatile Resistive Switching Characteristics of CCTO Films
(2011-03-01)
Lin, Chun-Chieh
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Chang, Yi-Peng
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Ho, Chia-Cheng
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Shen, Yu-Shu
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Chiou, Bi-Shiou
A novel material CaCu(3)Ti(4)O(12) (CCTO) for resistive random access memory (RRAM) application was prepared by sol-gel spin-coating method. Our previous studies indicated that the CCTO possesses stable resistive switching behavior. In this work, the effects of the top electrode (TE) material on the resistive switching characteristics of CCTO films are investigated. It indicates the work function of the TE is an important factor on the resistive switching properties. Successive resistive switching was observed for electrode materials of Ni, Pd, and Pt. Furthermore, optimized consideration of the electrode material for RRAM is also studied.
Effects of accumulated laser pulses on (Pb,Sr)TiO(3) films post-excimer laser annealed at low temperatures
(2007-08-01)
Wang, Jyh-Liang
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Lai, Yi-Sheng
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Chiou, Bi-Shiou
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Shye, Der-Chi
;
Hwang, Chuan-Chou
In this article, we report the effect of excimer laser annealing (ELA) on the characteristics of (Pb,Sr)TiO(3) (PSrT) films. The unirradiated and irradiated films are characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy, X-ray diffractometer (XRD), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). It is found that the crystallinity is improved and the oxygen content is increased by ELA. Besides, the surface morphology becomes rough after ELA. Moreover, PSrT films irradiated by ELA are found to increase the grain size near the surface. The material properties of unirradiated and irradiated films, as well as the characteristics of PSrT films irradiated with various laser pulses, will be explored in this study. (c) 2007 Elsevier B.V. All rights reserved.
Effects of accumulated laser pulses on (Pb,Sr)TiO3 films post-excimer laser annealed at low temperatures
(2007-08-01)
Wang, Jyh-Liang
;
Lai, Yi-Sheng
;
Chiou, Bi-Shiou
;
Shye, Der-Chi
;
Hwang, Chuan-Chou
In this article, we report the effect of excimer laser annealing (ELA) on the characteristics of (Pb,Sr)TiO3 (PSrT) films. The unirradiated and irradiated films are characterized by atomic force microscope (AFM), X-ray photoelectron spectroscopy, X-ray diffractometer (XRD), transmission electron microscopy (TEM), and electron energy loss spectroscopy (EELS). It is found that the crystallinity is improved and the oxygen content is increased by ELA. Besides, the surface morphology becomes rough after ELA. Moreover, PSrT films irradiated by ELA are found to increase the grain size near the surface. The material properties of unirradiated and irradiated films, as well as the characteristics of PSrT films irradiated with various laser pulses, will be explored in this study. (c) 2007 Elsevier B.V. All rights reserved.
Effects of annealing temperature on the resistance switching behavior of CaCu(3)Ti(4)O(12) films
(2008-12-01)
Shen, Yu-Shu
;
Chiou, Bi-Shiou
;
Ho, Chia-Cheng
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
In this study, a novel material CaCu(3)Ti(4)O(12) (CCTO), for resistance random access memory application, was prepared by sol-gel method and annealed at various temperatures. The crystallinity and microstructure of CCTO film, improve as annealing temperature increases. The CCTO films annealed at 800 degrees C and above endure more switching cycles (> 1000) and exhibit a small degradation of the resistance ratio between the high resistance state and the low resistance state than those annealed at 700 degrees C do. The correlation between resistance switching behaviors and film microstructure is discussed. (C) 2008 Elsevier B.V. All rights reserved.
Effects of annealing temperature on the resistance switching behavior of CaCu3Ti4O12 films
(2008-12-01)
Shen, Yu-Shu
;
Chiou, Bi-Shiou
;
Ho, Chia-Cheng
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
In this study, a novel material CaCu3Ti4O12 (CCTO), for resistance random access memory application, was prepared by sol-gel method and annealed at various temperatures. The crystallinity and microstructure of CCTO film, improve as annealing temperature increases. The CCTO films annealed at 800 degrees C and above endure more switching cycles (> 1000) and exhibit a small degradation of the resistance ratio between the high resistance state and the low resistance state than those annealed at 700 degrees C do. The correlation between resistance switching behaviors and film microstructure is discussed. (C) 2008 Elsevier B.V. All rights reserved.
Effects of plasma treatment on the high frequency characteristics of Cu/Ta/hydrogen silsesquioxane (HSQ) system and electrical behaviors of Cu/Ta/HSQ/Pt MIM capacitors
(2007-04-01)
Ho, Chia-Cheng
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Chiou, Bi-Shiou
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
;
Department of Electronics Engineering and Institute of Electronics
With the increasing of the operating frequencies, insertion loss, signal propagation delay, and parasitic coupling capacitance become the significant problems. Small capacitance (C) between interconnects is required to reduce the crosstalk, insertion loss, and RC delay associated with the metal interconnect system. Therefore, the interconnect with low dielectric constant (k) material is required. Implementation of Cu/low-k dielectric is used for reducing insertion loss, RC delay, crosstalk noises, etc. In this work, Cu-hydrogen silsesquioxane (HSQ) systems are studied. Ammonia (NH3) plasma is employed for the nitridation of HSQ. The effects of NH3 plasma treatments on the high frequency characteristics (100 MHz to 20 GHz) of the interconnect structure Cu/Ta/HSQ and electrical behaviors of Cu/Ta/HSQ/Pt MIM capacitors are evaluated. Auger electron spectroscopy (AES) results suggest the diffusion of oxygen and copper atoms during copper annealing. This raises resistance of Cu interconnect and increases the conductance of the HSQ films. Hence, 400 degrees C-annealed Cu/Ta/HSQ interconnect systems become lossy at high frequencies (> 2 GHz). Ammonia (NH3) plasma bombardments break some of the Si-H bonds and the resulting dangling Si bonds increase the moisture absorption. Meanwhile, NH3 plasma treatments reduce the leakage current by passivating the Si dangling bond and forming silicon nitride. The absorption of moisture and/or the formation of SiNx result in high dielectric constant of HSQ after prolonged NH3 plasma bombardment. The dielectric constant of HSQ decreases and then increases with the increase of NH3 plasma treatment time and a minimum dielectric constant of 2.2 is obtained after 50 s NH3 plasma treatment at 200 W. Among various specimens in this study, the smallest insertion loss is 1.97 dB/mm at 20 GHz for the 400 degrees C-annealed Cu/Ta/HSQ (NH3-plasma-treated for 50 s). Appropriate NH3-plasma bombardment helps to form a thin SiNx barrier layer which prevents the diffusion of oxygen without increasing the dielectric constant of the Cu-HSQ interconnect system. The leakage currents versus electric field characteristics suggest that a Schottky emission dominate conduction mechanism. (c) 2007 Elsevier B.V. All rights reserved.
Electrical properties of high-kappa praseodymium oxide polycrystalline silicon thin-film transistors with nitrogen implantation
(2008-02-01)
Deng, Chih-Kang
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Chang, Hong-Ren
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Chiou, Bi-Shiou
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電子工程學系及電子研究所
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Department of Electronics Engineering and Institute of Electronics
This paper demonstrates the polycrystalline silicon (poly-Si) thin-film transistors (TFTs) with high-kappa praseodymium oxide (Pr(2)O(3)) gate dielectric and nitrogen implantation to achieve high-performance characteristics for the first time. Nitrogen atoms with various dosages are implanted into amorphous silicon (alpha-Si) film to passivate the grain boundary trap states during solid-phase crystallization (SPC) annealing. From experimental results, the electrical characteristics of the Pr(2)O(3) poly-Si TFT implanted with the nitrogen dosage of 5 x 10(12) cm(-2) could be greatly improved. In addition, a better hot-harrier immunity of high-kappa Pr(2)O(3) poly-Si TFT could be also obtained.
Ferroelectricity and negative temperature coefficient of resistance in pulsed-laser-deposited (Pb, Sr) TiO(3) films
(2008-04-21)
Wang, Jyh-Liang
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Lai, Yi-Sheng
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Liou, Sz-Chian
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Tsai, Chun-Chien
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Chiou, Bi-Shiou
(Pb, Sr)TiO(3) films deposited on Pt/SiO(2)/Si substrates by pulsed-laser deposition (PLD) at 400 degrees C with oxygen pressures ranging from 50 to 200 mTorr have been investigated. The paraelectricity-to-ferroelectricity transition of films depends on the oxygen pressure during deposition. Films deposited at 200 mTorr exhibit paraelectric-like nature, whereas films deposited at lower pressures present the ferroelectric characteristic. The (Pb, Sr) TiO(3) film is found to exhibit a negative temperature coefficient of resistance (NTCR) at the measurement temperature ranging from 30 to 390 degrees C. This work demonstrates that the ferroelectricity/paraelectricity and the temperature coefficient of resistance of (Pb, Sr) TiO(3) films could be controlled by oxygen pressures during PLD.
Formation of cobalt-silicide nanocrystals in Ge-doped dielectric layer for the application on nonvolatile memory
(2008-04-14)
Hu, Chih-Wei
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Chang, Ting-Chang
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Liu, Po-Tsun
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Tu, Chun-Hao
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Lee, Sheng-Kai
In this work, Ge-doped cobalt-silicon thin film was synthesized using a cosputter system (Co and Si(0.5)Ge(0.5)). The deposited film was annealed in oxygen ambient at 650 degrees C to form cobalt-silicide nanocrystals. The formation of isolated silicide nanocrystals was confirmed by transmission electron microscopy and x-ray photoelectron spectroscopy analysis. In metal-oxide-insulator-oxide-silicon structure, a significant electrical hysteresis is observed and attributed by the presence of the cobalt-silicide nanocrystals and the oxidized Ge elements. (C) 2008 American Institute of Physics.
Hybrid Optical Access Network Integrating Baseband and Radio Signals Transmitted on a Single Wavelength
(2007)
Lin, Chun-Ting
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Peng, Peng-Chun
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Chen, Jason (Jyehong)
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Peng, Cheng-Feng
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Peng, Wei-Ren
We propose a hybrid optical access network integrating FTTH and RoF systems sharing a single distributed infrastructure. After transmission over 50km optical fiber, power penalties of baseband and RF signals are less than 0.2dB. (C) 2007 Optical Society of America
Hybrid optical access network integrating fiber-to-the-home and radio-over-fiber systems
(2007-03-01)
Lin, Chun-Ting
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Chen, Jason (Jyehong)
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Peng, Peng-Chun
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Peng, Cheng-Feng
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Peng, Wei-Ren
Hybrid optical access networks, integrating fiber-to-the-home (FTTH) and radio-over-fiber (RoF) systems that share a single distributed infrastructure, are promising for future multiservice access networks. The primary concern is to enable RoF and FTTH systems to transmit both radio-frequency (RF) and baseband (BB) signals on a single wavelength over a single fiber. This study experimentally demonstrates simultaneous generation and transmission of a wired-line BB signal and a wireless RF signal on a single wavelength, using one external modulator. The hybrid signals transmitted over standard single-mode fiber (SSMF) do not suffer from periodic performance fading due to fiber dispersion. Following transmission over 50-km SSMF, the power penalties of both RF and BB signals are less than 0.2 dB.
Impedance Spectroscopy of CaCu(3)Ti(4)O(12) Films Showing Resistive Switching
(2009-01-01)
Shen, Yu-Shu
;
Ho, Chia-Cheng
;
Chiou, Bi-Shiou
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
CaCu(3)Ti(4)O(12) (CCTO), for resistance random access memory (RRAM) application, was prepared by the sol-gel method. Our preliminary study indicates that CCTO possesses the resistive switching behaviors of RRAM. In this work, the resistance switching characteristics of CCTO films were investigated. The impedance spectroscopy was applied to CCTO films during the switching cycle. Based on the results observed by impedance spectroscopy, the conduction mechanisms of the CCTO RRAMs at the original, ON, and OFF states were explored.
Impedance Spectroscopy of CaCu3Ti4O12 Films Showing Resistive Switching
(2009-01-01)
Shen, Yu-Shu
;
Ho, Chia-Cheng
;
Chiou, Bi-Shiou
;
電子工程學系及電子研究所
;
Innovative Packaging Research Center
CaCu3Ti4O12 (CCTO), for resistance random access memory (RRAM) application, was prepared by the sol-gel method. Our preliminary study indicates that CCTO possesses the resistive switching behaviors of RRAM. In this work, the resistance switching characteristics of CCTO films were investigated. The impedance spectroscopy was applied to CCTO films during the switching cycle. Based on the results observed by impedance spectroscopy, the conduction mechanisms of the CCTO RRAMs at the original, ON, and OFF states were explored.
Improvement of electrical properties of Ba(0.7)Sr(0.3)TiO(3) capacitors with an inserted nano-Cr interlayer
(2008-07-01)
Ho, Chia-Cheng
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Chiou, Bi-Shiou
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Chang, Li-Chun
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電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The metal-insulator-metal (MIM) capacitors were prepared with Ba(0.7)Sr(0.3)TiO(3)/Cr/Ba(0.7)Sr(0.3)TiO(3) (BST/Cr/BST) dielectric and Pt electrode. The multilayer BST/Cr/BST was sputtered onto Pt/Ti/SiO(2)/Si substrate. The presence of nano-Cr interlayer affects the electrical properties of the capacitors. The temperature coefficient of capacitance (TCC) of capacitors with 2 nm Cr is about 69% of that of capacitors without Cr. In a previous work, the formation of the TiO(2) secondary phase was found after the BST/Cr/BST dielectrics were annealed at 1023 K in O(2) atmosphere for 1 h. It is suggested that the nano-Cr interlayer as a catalyst leads to the TiO(2) formation during the annealing in O(2) atmosphere. The negative value of TCC of BST can be compensated by the positive TCC of TiO(2), and the temperature stability in the dielectric constant can be realized for capacitors with nano-Cr interlayer. The voltage stability of BST is also improved with the insertion of nano-Cr interlayer, and the quadratic coefficient in voltage coefficient of capacitance (VCC) of Pt/BST/Cr(2 nm)/BST/Pt is about 30% of that of the BST capacitor without Cr. The effects of Cr thickness on TCC, VCC, dissipation factor, and leakage current density of Pt/BST/Cr/BST/Pt parallel plate capacitors are investigated.