Browsing by Author "Huang, TY"

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A dual-gate-controlled single-electron transistor using self-aligned polysilicon sidewall spacer gates on silicon-on-insulator nanowire
(2004-03-01)
Hu, SF
;
Wu, YC
;
Sung, CL
;
Chang, CY
;
Huang, TY
A dual-gate-controlled single-electron transistor was fabricated by using self-aligned polysilicon sidewall spacer gates on a silicon-on-insulator nanowire. The quantum dot formed by the electric field effect of the dual-gate structure was miniaturized to smaller than the state-of-the-art feature size, through a combination of electron beam lithography, oxidation, and polysilicon sidewall spacer gate formation processes. The device shows typical MOSFET I-V characteristics at room temperature. However, the Coulomb gap and Coulomb oscillations are clearly observed at 4 K.
A model for photoresist-induced charging damage in ultra-thin gate oxides
(1997)
Lin, HC
;
Chien, CH
;
Wang, MF
;
Huang, TY
;
Chang, CY
The role of photoresist (PR) in affecting the gate oxide damage during plasma processing boas reexamined in this work. if was observed that, during the O-2 plasma ashing, more severe antenna effect may occur in devices with PR covering. A model is proposed to explain this phenomenon. This model considers the ability of plasma current injection through the substrate contacts, which are hindered by PR covering, to adjust the potential difference between gate electrode and substrate. We Sound that the presence of PR, antenna ratio, and gate-oxide thickness are all important parameters for charging damage effect.
A multilevel interconnect technology with intrametal air gap for high-performance 0.25-mu m-and-beyond devices manufacturing
(1999-11-01)
Lin, M
;
Chang, CY
;
Huang, TY
;
Lin, ML
;
電子工程學系及電子研究所
A multilevel interconnect technology with an intra metal air gap has been developed to reduce the interconnect delay time for versatile. and quick turnaround-time foundry manufacturing. The air-gap method has been successfully applied to 0.25 mu m IC technology and shown to be effective in reducing the parasitic interconnect capacitance. Measurements of various ring oscillators confirm that the smallest delay time is indeed achieved with the air-gap method, compared with other methods using either conventional high-density-plasma (HDP) oxide or low-dielectric-constant spin-on-glass (SOG) as the gap-filling insulating materials. Moreover, the oscillator delay time is found to depend critically on not only the size of the air gap, but also the position of the air gap. Best results in terms of delay time reduction are obtained when the air-gap is positioned in the middle between the two metal lines, and extends both above and below the metal lines to effectively reduce the fringing capacitance. We have also measured the leakage current between adjacent metal lines and confirmed that our new metal intel connect structure with an air gap does not exhibit any appreciable leakage and appears to be suitable For high-performance foundry applications. Lastly, the polarization and thermal characteristics of the air-gap structure were compared with conventional gap-filling methods.
A new method to extract MOSFET threshold voltage, effective channel length, and channel mobility using S-parameter measurement
(2004-05-01)
Chen, HY
;
Chen, KM
;
Huang, GW
;
Chang, CY
;
Huang, TY
In this work, a simple method for extracting MOSFET threshold voltage, effective channel length and channel mobility by using S-parameter measurement is presented. In the new method, the dependence between the channel conductivity and applied gate voltage of the MOSFET device is cleverly utilized to extract the threshold voltage, while biasing the drain node of the device at zero voltage during measurement. Moreover, the effective channel length and channel mobility can also be obtained with the same measurement. Furthermore, all the physical parameters can be extracted directly on the modeling devices without relying on specifically designed test devices. Most important of all, only one S-parameter measurement is required for each device under test (DUT), making the proposed extraction method promising for automatic measurement applications.
A novel lightly doped drain polysilicon thin-film transistor with oxide sidewall spacer formed by one-step selective liquid phase deposition
(1999-08-01)
Shih, PS
;
Chang, CY
;
Chang, TC
;
Huang, TY
;
Peng, DZ
We have proposed and successfully demonstrated a novel process for fabricating lightly doped drain (LDD) polycrystalline silicon thin-film transistors (TFT's), The oxide sidewall spacer in the new process is formed by a simple one-step selective liquid phase deposition (LPD) oxide performed at 23 degrees C, Devices fabricated with the new process exhibit a lower leakage current and a better ON/OFF current ratio than non-LDD control devices. Since the apparatus used for LPD oxide deposition is simple and inexpensive, the new process appears to be quite promising for future high-performance poly-Si TFT fabrication.
A novel methodology for extracting effective density-of-states in poly-Si thin-film transistors
(2004)
Lin, HC
;
Yeh, KL
;
Lee, MH
;
Su, YC
;
Huang, TY
A novel methodology that greatly simplifies the procedure of extracting the effective density-of-states (DOS) in polycrystalline-Si thin-film transistors (poly-Si TFTs) is proposed and demonstrated. The characterization is performed on a Schottky barrier (SB) TFT with electrical source/drain extensions induced by a field-plate. Only one single device and two simple subthreshold I-V measurements at room temperature are needed for full band-gap DOS extraction. Impacts of different process treatments are clearly resolved using this methodology.
A novel thin-film transistor with self-aligned field induced drain
(2001-01-01)
Lin, HC
;
Yu, CM
;
Lin, CY
;
Yeh, KL
;
Huang, TY
In this letter, a novel thin-film transistor with a self-aligned field-induced-drain (SAFID) structure is reported for the first time. The new SAFID TFT features a self-aligned sidewall spacer located on top of the drain offset region to set its effective length, and a bottom gate (or field plate) situated under the drain offset region to electrically induce the field-induced-drain (FID). So, unlike the conventional off-set-gated TFTs with their effective FID length set by two separate photolithographic masking layers, the new SAFID is totally immune to photomasking misalignment errors, while enjoying the low off-state leakage as well as high turn-on characteristics inherent in the FID structure. Polycrystalline silicon TFTs with the new SAFID structure have been successfully fabricated with significant improvement in the on/off current ratio.
A silicon nanowire with a Coulomb blockade effect at room temperature
(2002-05-17)
Hu, SF
;
Wong, WZ
;
Liu, SS
;
Wu, YC
;
Sung, CL
An extremely narrow and thin silicon wire has been fabricated on a silicon-on-insulator wafer (see Figure). The room-temperature Coulomb blockade effects as well as the influence of a capacitively coupled gate on the transport properties of this conducting silicon quantum wire are studied. The results obtained are encouraging for the application of such wires in single-electron transistors.
A simple and low-cost method to fabricate TFTs with poly-Si nanowire channel
(2005-09-01)
Lin, HC
;
Lee, MH
;
Su, CJ
;
Huang, TY
;
Lee, CC
A very simple and low-cost scheme is proposed for fabricating thin-film transistors with poly-Si nanowire (NW) channels. In this scheme, the poly-Si NW channel is formed by cleverly employing the poly-Si sidewall spacer technique. In addition, the poly-Si NW channel is genuinely exposed to the environment after the poly-Si sidewall spacer formation in the new scheme. This unique feature, together with its simplicity and low-cost, makes this approach very suitable for applications and manufacturing of bio-logic sensing devices. Good device performance is demonstrated in this letter.
A study of parasitic resistance effects in thin-channel polycrystalline silicon TFTs with tungsten-clad source/drain
(2003-08-01)
Zan, HW
;
Chang, TC
;
Shih, PS
;
Peng, DZ
;
Kuo, PY
With selectively-deposited tungsten film grown on source/drain regions, the parasitic source/drain resistance of thin-channel polycrystalline silicon (poly-Si) thin film transistors can be greatly reduced, leading to the improvement of device driving ability. After extracting the parasitic resistance from characteristics of devices with different channel length, the influences of parasitic resistance on device performances were discussed. A physically-based equation containing the parasitic resistance effects was derived to explain the behavior of linear transconductance under high gate voltage. Good agreements were found between calculated and measured data for both the thin-channel devices with or without tungsten-clad source/drain structure.
A study on the radiation hardness of flash cell with horn-shaped floating-gate
(1997-09-01)
Huang, TY
;
Jong, FC
;
Chao, TS
;
Lin, HC
;
Leu, LY
The effects of radiation on the characteristics of split-gate electrical erasable programmable read only memory (EEPROM)/flash cells with recently-proposed horn-shaped floating gates are studied in terms of cell read current; data retention, cycling endurance, program/erase efficiency, threshold voltage and junction leakage. Our results show that the cells appear to survive after 1 Mrad (Si) Co-60 irradiation. Moreover, the after-irradiation cell read current actually increases in the ''erase'' (i.e., low-threshold voltage, high-conducting) state (i.e., improves), albeit the cell read current also increases in the ''program'' (i.e., high-threshold voltage, low-conducting) state (i.e., a degradation). Our results also show that, despite an improvement in the initial read current in the ''erase'' state immediately after radiation, the write/erase cycling endurance of the flash cells is significantly impeded after irradiation, due to a much faster ''window closure'' rate in the ''erase'' state, although the cell read current is found to remain relatively stable in the ''program'' state after cycling.
A study on the radiation hardness of flash cell with horn-shaped floating-gate
(1997-09-01)
Huang, TY
;
Jong, FC
;
Chao, TS
;
Lin, HC
;
Leu, LY
The effects of radiation on the characteristics of split-gate electrical erasable programmable read only memory (EEPROM)/flash cells with recently-proposed horn-shaped floating gates are studied in terms of cell read current; data retention, cycling endurance, program/erase efficiency, threshold voltage and junction leakage. Our results show that the cells appear to survive after 1 Mrad (Si) Co-60 irradiation. Moreover, the after-irradiation cell read current actually increases in the ''erase'' (i.e., low-threshold voltage, high-conducting) state (i.e., improves), albeit the cell read current also increases in the ''program'' (i.e., high-threshold voltage, low-conducting) state (i.e., a degradation). Our results also show that, despite an improvement in the initial read current in the ''erase'' state immediately after radiation, the write/erase cycling endurance of the flash cells is significantly impeded after irradiation, due to a much faster ''window closure'' rate in the ''erase'' state, although the cell read current is found to remain relatively stable in the ''program'' state after cycling.
Ambipolar Schottky barrier silicon-on-insulator metal-oxide-semiconductor transistors
(2003-02-01)
Lin, HC
;
Wang, MF
;
Lu, CY
;
Huang, TY
;
電子工程學系及電子研究所
A novel Schottky barrier silicon-on-insulator metal-oxide-semiconductor field-effect transistor featuring metallic source/drain and an electrical drain junction has been fabricated and characterized. The formation of electrical drain junction, or the field-induced drain (FID), is controlled by a metal field-plate overlying the passivation oxide. Excellent ambipolar operation is demonstrated on the device. Specifically, on/off current ratios up to 10(8) and 10(7) are observed for p- and n-channel operations, respectively. Meanwhile, the off-state leakage current shows very weak dependence on the voltage difference between the main-gate and the drain, highlighting the effectiveness of FID. Finally, negative differential conductance effect is observed for n-channel operation, which is identified as due to dynamic hot electron trapping during device characterization. (C) 2002 Elsevier Science Ltd. All rights reserved.
Ambipolar Schottky-barrier TFTs
(2002-02-01)
Lin, HC
;
Yeh, KL
;
Huang, TY
;
Huang, RG
;
Sze, SM
A novel Schottky-barrier metal-oxide-semiconductor thin-film transistor (SBTFT) was successfully demonstrated and characterized. The new SBTFT device features a fleld-induced-drain (FID) region, which is controlled by a metal field-plate lying on top of the passivation oxide. The FED region is sandwiched between the silicided drain and the active channel region. Carrier types and the conductivity of the transistor are controlled by the metal field-plate. The device is thus capable of ambipolar operation. Excellent ambipolar performance with on/off current ratios over 10(6) for both p- and n-channel operations was realized simultaneously on the same device fabricated with polysilicon active layer. Moreover, the off-state leakage current shows very weak dependence on the gate-to-drain voltage difference with the FID structure. Finally, the effects of FED length are explored.
An anomalous crossover in Vth roll-off for indium-doped nMOSFETs
(2000-09-01)
Chang, SJ
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Chang, CY
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Chen, CM
;
Chou, JW
;
Chao, TS
The effects of indium channel implant energy on short-channel effect (SCE) and narrow channel effect (NCE) were studied on NMOS devices down to 0.1 mu m channel length. An anomalous crossover in Vth roll-off curves was observed, for the first time, on indium-implanted splits with different implant energies. This intriguing finding, together with the observed reduction in reverse narrow channel effect (RNCE) and effective channel length with reducing indium implant energy, can be consistently explained by the suppression of transient enhanced diffusion (TED) of channel impurity due to indium deactivation.
An improved approach for small-signal equivalent-circuit parameter determination of InGaP/GaAs HBT
(2005-03-05)
Chen, HY
;
Chen, KM
;
Huang, GW
;
Chang, CY
;
Huang, TY
In this paper, an improved method for extracting the small-signal equivalent-circuit elements of an HBT is proposed. A more general HBT equivalent circuit and a more general explicit equation on the total extrinsic elements are introduced. Linear least-square algorithms are cleverly adopted to reduce the number of error function. As a result, the modified approach can yield a better fit between the measured and simulated S-parameters over the conventional method. (C) 2005 Wiley Periodicals, Inc.
Analysis of narrow width effects in polycrystalline silicon thin film transistors
(2003-01-01)
Zan, HW
;
Chang, TC
;
Shih, PS
;
Peng, DZ
;
Huang, TY
In this study, narrow width effects of polycrystalline silicon thin film transistors (poly-Si TFTs) are investigated. With reducing channel width, TFT characteristics such as. mobility, threshold voltage, and subthreshold swing are found to improve dramatically. To gain insight on the origin of the narrow width effects, a physically-based model is proposed to simulate the output characteristics of poly-Si TFTs. Excellent fitting with the experimental data is observed over a wide range of drain bias, gate bias, and channel width. Our model shows that both the deep state density and-tail state density are reduced with reducing channel width, thus accounting for the improved TFT characteristics. In addition, subthreshold swings of poly-Si TFTs with various channel widths and lengths are compared. It is found that the subthreshold swings of poly-Si TFTs with the same channel area are identical, indicating that the grain-boundary trap density is reduced due to the reduction of channel area.
Application of field-induced source/drain Schottky metal-oxide-semiconductor to fin-like body field-effect transistor
(2002-06-01)
Lin, HC
;
Wang, MF
;
Hou, FJ
;
Liu, JT
;
Huang, TY
A novel Schottky barrier silicon-on-insulator (SOI) metal-oxide-semiconductor field effect transistor (MOSFET) device was proposed and demonstrated, The new device features a silicide source/drain and field-induced source/drain (S/D) extensions. Excellent ambipolar performance with a near-ideal sub-threshold slope (similar to 60 mV/decade) and high on-/off-state current ratio (comparable to or higher than 10(9)) is realized, for the first time, on a single device. These encouraging results suggest that the new device may be suitable for some niche applications requiring simple and low-temperature processing of complementary metal-oxide-semiconductor(CMOS)-like devices.
Assessment of driver's driving performance and alertness using EEG-based fuzzy neural networks
(2005)
Lin, CT
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Chen, YC
;
Wu, RC
;
Liang, SF
;
Huang, TY
Traffic fatalities in recent years have become a serious concern to our society. Accidents caused by drivers' drowsiness have a high fatality rate due to the decline of drivers' abilities in perception, recognition, and vehicle control abilities while sleepy. Preventing such an accident requires a technique for detecting, estimating, and predicting the level of alertness of a driver and a mechanism to maintain the driver's maximum performance of driving. This paper proposed a system that combines electroencephalogram (EEG) power spectra estimation, independent component analysis and fuzzy neural network models to estimate drivers' cognitive state in a dynamic virtual-reality-based driving environment. Experimental results show that the quantitative driving performance can be accurately and successfully estimated through analyzing driver's EEG signals by the proposed system.
Automated information. mining on multimedia TV news archives
(2005)
Lai, PS
;
Cheng, SS
;
Sun, SY
;
Huang, TY
;
Su, JM
This paper addresses an integrated information mining techniques for multimedia TV-news archive. The utilizes techniques from the fields of acoustic, image, and video analysis, for information retrieval on news story title, newsman and scene identification. The goal is to construct a compact yet meaningful abstraction of broadcast news video, allowing users to browse through large amounts of data in a non-linear fashion with flexibility and efficiency. By using acoustic analysis, the system can classify video into news versus commercials, with 90% accuracy on a data set of 400 hours TV-news recorded off the air from July 2003 to August of 2004. By applying speaker identification and/or image detection techniques, each news stories can be segmented with an accuracy of 96%. On screen captions or subtitles are recognized by OCR techniques to produce the text title of each news stories. The extracted title words can be used to link or to navigate more related News contents on the WWW. In cooperation with facial and scene analysis and recognition techniques, OCR results can provide users with multimodality query for specific news stories. Some experimental results are presented and discussed for the system reliability and performance evaluation and comparison.