Browsing by Author "Chen, TJ"

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Application of plasma immersion ion implantation doping to low-temperature processed poly-Si TFT's
(1998-11-01)
Yeh, CF
;
Chen, TJ
;
Liu, C
;
Shao, JQ
;
Cheung, NW
This work applied, for the first time, plasma immersion ion implantation (PIII) for source/drain doping on low-temperature processed polysilicon thin-film transistors (poly-Si TFT's), Experimental results indicate that PIII doping can provide adequate dopant concentration and junction depth for source/drain. In addition, H-2-diluted phosphorus pill can promote dopant activation more efficiently during RTA at 600 degrees C than with conventional ion implantation (II) technology. The excellent characteristics of PIII doped poly-Si TFT's resemble those of conventional II doped ones.
Closure to "Passive earth pressure with critical state concept" by Yung-Show Fang, Ying-Chieh Ho, and Tsang-Jiang Chen
(2003-10-01)
Fang, YS
;
Ho, YC
;
Chen, TJ
;
土木工程學系
;
Department of Civil Engineering
Effect of processing temperature on polysilicon thin-film transistors with liquid-phase deposited oxide as gate insulator
(1997)
Yeh, CF
;
Chen, TJ
;
Jeng, JN
;
交大名義發表
;
電子工程學系及電子研究所
Liquid-phase deposited (LPD) oxide has been successfully applied as gate insulator to low-temperature processed polysilicon thin-film transistors (poly-Si TFTs). This paper assesses the feasibility of applying LPD oxide to high-temperature processed (HTP) TFTs. The high-temperature treatments like gate-oxide annealing and dopant activation provide excellent improvement in the characteristics of poly-Si TFTs with LPD gate oxides. These high-temperature treated devices show effective hydrogenation using the NH3 plasma treatment. The results imply that novel LPD gate oxide technologies can lead to replacement of thermal gate oxide with HTP poly Si TFTs. The reliability of HTP poly-Si TFTs with LPD gate oxides was also investigated.
Effects of process temperature on polysilicon thin film transistors with liquid-phase deposited oxides as gate insulators
(1997-10-01)
Yeh, CF
;
Chen, TJ
;
Jeng, JN
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Liquid-phase deposited (LPD) oxide has previously been successfully applied to low temperature processed polysilicon thin film transistors (poly-Si TFTs) as a gate insulator. This paper shows the feasibility of applying room temperature deposited LPD oxide to high temperature processed devices. The thermal effects of high temperature processing on poly-Si TFTs including postoxide annealing and dopant activation have been investigated. These high temperature treatments show excellent improvement in device characteristics. In addition, the novel devices also show considerably more efficient hydrogenation during NH3-plasma treatment, and their reliability under de electrical stress appears similar to that of conventional poly-Si TFTs.
Highly reliable liquid-phase deposited SiO2 with nitrous oxide plasma post-treatment for low temperature processed poly-Si TFT's
(1998)
Yeh, CF
;
Chen, DC
;
Lu, CY
;
Liu, C
;
Lee, ST
Low temperature (similar to 300 degrees C) N2O plasma annealing for liquid-phase deposited (LPD) gate oxide has been proposed for the first time. Physicochemical and electrical characterizations show that the N2O-treated LPD-SiO2 improves breakdown field, interface state density, and Si-rich phenomenon. This novel technology has been also successfully applied to LTP poly-Si TFT's, which reveal excellent characteristics and reliability. It is believed that the N2O plasma post-treatment not only improves the oxide quality, but also passivates the trap states in poly-Si channel.
Highly reliable liquid-phase-deposited SiO2 with nitrous oxide plasma post-treatment for low-temperature-processed polysilicon thin film transistors
(2002-10-01)
Yeh, CF
;
Chen, DCH
;
Lu, CY
;
Liu, C
;
Lee, ST
Low-temperature ( similar to 300 C) N2O-plasma post-treatment for liquid-phase-deposited (LPD) gate oxide has been proposed for the first time. This treatment successfully takes the place of conventional furnace annealing in O-2 ambient. Results of physicochemical and electrical characteristics shock that N2O-plasma post-treated LPD-SiO2 has a high electrical breakdown field and low interface State density. In addition. N2O-plasma treatment also improves the Si-rich phenomenon of LPD-SiO2. From the comparison with pure N2O-plasma oxidation film, LPD-SiO2 with its short re-oxidation time in N2O plasma plays an important role in relieving interfacial stress. Finally, the novel technology is applied to the gate oxide of low-temperature-processed (LTP) polysilicon thin film transistors (poly-Si TFTs). The device performance reveals excellent electrical characteristics, and the reliability shows a satisfactory result. as well as the gate oxide reliability. It is believed that the N2O-plasma post-treatment not only improves the oxide quality, but also effectively passivates the trap states of poly-Si TFTs.
Hydrogenation of polysilicon thin-film transistor in a planar inductive H-2/Ar discharge
(1999-05-01)
Yeh, CF
;
Chen, TJ
;
Liu, C
;
Gudmundsson, JT
;
Lieberman, MA
A planar inductive discharge is used to hydrogenate polysilicon thin-film transistors (poly-Si TFT's). Experimental results indicate that inductive discharges operate at higher plasma densities, thereby capable of shortening the hydrogenation time. In addition, to promote the ionization of hydrogen, Ar gas is also introduced to H-2 plasma during hydrogenation. Furthermore, me discuss the mechanism of Ar enhanced hydrogenation and the characteristics of H-2/Ar mixed plasma. Moreover, the posthydrogenation anneal is utilized to further enhance passivation efficiency and improve the reliability of poly-Si TFT's.
In-line fiber polarization selector and intensity modulator
(1997)
Chen, TJ
;
Hsu, JM
;
Chen, SH
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光電工程學系
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Department of Photonics
Liquid-crystal-based fiber components that exploit the high birefringence and electrooptic effect of liquid crystals, are versatile. A single-mode fiber enclosed with planar-aligned liquid crystals is reported on in this paper. The fiber was etched nearly to its core. The output light was exercised through the evanescent field coupling between the fiber and surrounding liquid crystals. To achieve an effective access to the evanescent field, the etch depth was studied first. When the fiber was etched to 10-mu m diameter, obvious light leakage occurred. Once the electric field was switched on, the polarization selection and intensity modulation were examined. A theoretical description of the optical characteristics were also given.
In-situ O-2-plasma passivation effect on poly-Si TFTs during ion plating capping oxide
(1997)
Yeh, CF
;
Chen, TJ
;
Lin, MT
;
Kao, JS
;
交大名義發表
A novel method has been developed to effectively reduce defect density in poly-Si thin-film transistors (TFTs) using ion plating (IF) oxides as capping layers. The characteristics of TFTs with TP capping oxides are superior to those of TFTs with TEOS capping oxides due to the in-situ O-2-plasma passivation effect during IP oxide deposition. The hydrogenation effect on the novel devices is not very evident because their trap-state density has been reduced by O-2 plasma. poly-Si TFTs with IP capping oxides still maintain good performance even stressing at 100 degrees C with a bias of 20 V.
Investigation of silicon oxide films prepared by room-temperature ion plating
(1998-01-15)
Yeh, CF
;
Chen, TJ
;
Fan, CL
;
Kao, JS
;
電子工程學系及電子研究所
To develop excellent silicon oxide film using low temperature method, ion plating (IP) oxide is investigated. Physicochemical characterizations of the IP oxide are studied using ellipsometry, Fourier transform infrared spectrometry, and P-etch rate measurement. The IP oxide is a high-density dielectric with strained bonds. Electrical characterizations are also analyzed using capacitance-voltage and current-voltage techniques through metal-oxide-semiconductor capacitors. The IP oxide has a low leakage current, a high breakdown field, and low interface state density. In addition, IP oxide annealed in N-2 ambient is also studied. After high-temperature annealing, the characteristics of IP oxide become comparable to those of thermal oxide. The novel oxide him is successfully applied as a gate insulator to low-temperature processed (less than or equal to 620 degrees C) polysilicon thin-film transistors. (C) 1998 American Institute of Physics.
Modification of Mononobe-Okabe theory
(1995-03-01)
Fang, YS
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Chen, TJ
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交大名義發表
;
National Chiao Tung University
O-2-plasma passivation effects on polysilicon thin film transistors using ion plating method
(1998-01-01)
Yeh, CF
;
Chen, TJ
;
Lin, MT
;
Kao, JS
;
電子工程學系及電子研究所
A novel method has been developed for efficiently reducing defect density in polysilicon thin film transistors using ion plated oxides as capping layers. The characteristics of these novel thin film transistors are superior to those of thin film transistors with plasma-enhanced chemical vapor deposited tetraethylorthosilicate capping oxides due to an in situ O-2-plasma passivation effect during ion plating oxide deposition. The passivation effect of a NH3 plasma on the novel devices was also studied. The in situ ion plating O-2 plasma shows a better passivation efficiency on trap states than the NH3 plasma. Polysilicon thin film transistors with ion plating capping oxides are hardly degraded even when stressed with a bias of 20 V at 100 degrees C.
Passivation effects of ion plating capping oxide on poly-Si TFTs
(1997)
Yeh, CF
;
Chen, TJ
;
Kao, JS
;
交大名義發表
;
電子工程學系及電子研究所
Passive earth pressure with critical state concept
(2002-08-01)
Fang, YS
;
Ho, YC
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Chen, TJ
;
土木工程學系
;
Department of Civil Engineering
This paper presents experimental data of earth pressure acting against a vertical rigid wall, which moved toward a mass of dry sand. The backfill had been placed in lifts to achieve relative densities of 38, 63, and 80%. The instrumented retaining-wall facility at National Chiao Tung University in Taiwan was used to investigate the effects of soil density on the development of earth pressure. Based on the experimental data, it has been found that the Coulomb and Terzaghi solutions calculated with the peak internal friction angle significantly overestimated the ultimate passive thrust for the retaining wall filled with dense sand. As the wall movement S exceeded 12% of the wall height H, the passive earth thrust would reach a constant value, regardless of the initial density of backfill. Under such a large wall movement, soils along the rupture surface had reached the critical state, and the shearing strength on the surface could be properly represented with the residual internal-friction angle. The ultimate passive earth pressure was successfully estimated by adopting the critical state concept to either Terzaghi or Coulomb theory.
Physical characteristics of N-2 annealing on room-temperature-deposited ion plating oxide
(1997-03-24)
Yeh, CF
;
Chen, TJ
;
Kao, JS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The effects of N-2 annealing on the physical properties of room-temperature-deposited ion plating (IF) oxide have been characterized. As-deposited IP oxide exhibits higher refractive index and dielectric constant values than high-temperature-annealed IP oxide. Strained bonds existing in as-deposited oxide can be relaxed by N-2 annealing depending on the annealing temperature. After annealing at 800 degrees C, the physical characteristics of IP oxide are comparable to those of thermal oxide. (C) 1997 American Institute of Physics.
Physical characteristics of N-2 annealing on room-temperature-deposited ion plating oxide
(1997-03-24)
Yeh, CF
;
Chen, TJ
;
Kao, JS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The effects of N-2 annealing on the physical properties of room-temperature-deposited ion plating (IF) oxide have been characterized. As-deposited IP oxide exhibits higher refractive index and dielectric constant values than high-temperature-annealed IP oxide. Strained bonds existing in as-deposited oxide can be relaxed by N-2 annealing depending on the annealing temperature. After annealing at 800 degrees C, the physical characteristics of IP oxide are comparable to those of thermal oxide. (C) 1997 American Institute of Physics.
Reduction of boundary friction in model tests
(2004-01-01)
Fang, YS
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Chen, TJ
;
Holtz, RD
;
Lee, WF
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土木工程學系
To model plane-strain conditions in the laboratory, the frictional resistance between the soil and side walls of the soil box should be reduced as much as possible. Methods commonly employed for this purpose include a latex sheet with silicon grease ("grease method") or multiple layers of thin plastic sheeting ("plastic sheet method"). Interface friction angles are often measured by direct shear-type tests. In this paper, a new sliding block testing device for measuring the friction at the interface between soil and different materials at low stress conditions is described. Interface friction angles for eight different methods for reducing boundary friction were investigated using the proposed testing method. Test results indicated that the friction angle obtained with the plastic sheet method is nearly independent of the normal stress. On the other hand, the interface friction angle of the grease method was quite high under low normal stress conditions. Thus, the plastic sheet method appears to be a more appropriate technique under low normal stress conditions to reduce the boundary friction for laboratory scale model tests. As compared with the grease method, advantages of the plastic sheet method include constant friction angles, less time for preparation and cleanup, and lower cost. To investigate their applicability, both lubrication systems were used in some large-scale laboratory-retaining wall experiments. Earth pressure measurements obtained near the sidewalls indicated that, under a low normal stress, the plastic sheet method was more effective in reducing sidewall friction.
Retaining walls damaged in the Chi-Chi earthquake
(2003-12-01)
Fang, YS
;
Yang, YC
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Chen, TJ
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土木工程學系
;
Department of Civil Engineering
This paper investigates the failure of three gravity walls due to the 1999 Chi-Chi earthquake. Characteristics of the damaged walls were carefully recorded and backfill materials behind the damaged walls were collected and tested in the laboratory. Both the simplified analysis based on the Mononobe-Okabe method and the simplified dynamic analysis based on the Richards-Elms method were adopted. For the first case, the sliding of concrete wall blocks along the construction joint was observed. It was found that, during the earthquake, the frictional resistance at the untreated construction joint was not sufficient to resist the dynamic lateral thrust. For the second case, the retaining wall settled significantly and tilted about its toe. Seismic analysis of the wall indicated that, under the same horizontal acceleration, the factor of safety against bearing capacity failure was lower than that against overturning and sliding. A stability check against bearing capacity failure for the retaining wall should never be neglected. For the third case, the retaining wall built on top of the Che-Lung-Pu fault was severely damaged by the fault rupture. During the earthquake, the vertical displacement of the hanging wall uplifted the backfill, causing the wall to overturn. Horizontal displacement of the hanging wall caused the wall to slide and the soil in front of the toe to heave.