Browsing by Author "Yang, JY"

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A CVD epitaxial deposition in a vertical barrel reactor: Process modeling using cluster-based fuzzy logic models
(1998-11-01)
Chiou, JC
;
Yang, JY
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A chemical vapor deposition (CVD) epitaxial deposition process modeling using fuzzy logic models (FLM's) has been proposed. The process modeling algorithm consists of a cluster estimation method and backpropagation algorithm to construct a number of modeling structures from the training data. A decision rule based on the multiple correlation factor is used to obtain the optimum structure of fuzzy model using the testing data. Upon the optimum structure has been reached, the gradient-descent method is used to refer the parameters of the final fuzzy model using both training and testing data. The algorithm has been applied to a nonlinear function and a vertical chemical vapor deposition process, The results demonstrate the efficiency and effectiveness of the proposed fuzzy logic model in comparison with existing fuzzy logic models and artificial neural network models.
A new simple and reliable method to form a textured Si surface for the fabrication of a tunnel oxide film
(1998-05-01)
Chang, KM
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Li, CH
;
Sheih, BS
;
Yang, JY
;
Wang, SW
In this work, a textured Si surface was formed with a new simple and reliable method for tunnel oxide fabrication. First, a thin poly-Si layer (12 nm thick) was deposited on Si surface and a 30-nm thick dry oxide film was then grown in O-2 ambient. This oxide film was served as a sacrificial oxide. The poly-Si film and Si substrate were both oxidized during thermal oxidization. After stripping this sacrificial oxide, a textured Si surface was obtained. Tunnel oxide grown on this textured Si surface has an asymmetrical J-E characteristics, less interface states generation and better reliability (larger Q(bd)) as compared to those of normal oxide.
A novel process and thermodynamic mechanisms of air gap formation for ULSI application
(2000-11-01)
Chang, KM
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Yang, JY
;
Chen, LW
;
Tseng, MH
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電子工程學系及電子研究所
In this study, a novel process to fill the gap between the metal lines on a wafer with air is developed. Reduction of the parasitic wire capacitance in ULSI has become an important issue for future high-speed and low-power applications. Use of low dielectric constant material as inter-level dielectric (ILD) can overcome this problem. Many new low dielectric constant materials are under study and lower dielectric constant and feasibility are the two goals of these researches. The gas-dielectric process has the lowest dielectric constant, 1.0, and its conceptual feasibility is demonstrated. Basic process characterization data, thermodynamic mechanism and requirements for air gap formation are also discussed. We calculated the relationship among the surface tension, the vaporization rate and atmospheric pressure to construct a model of the process window to show that this process is feasible and reproducible. Scanning electron microscope data show that a large area of air gap can be obtained. Basic electrical characteristics data such as I-V and C-V, measured and compared with the conventional PECVD process, show that the air gap has better isolation than PECVD process. (C) 2000 Elsevier Science S.A. All rights reserved.
A novel technology to form air gap for ULSI application
(1999-04-01)
Chang, KM
;
Yang, JY
;
Chen, LW
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
In this letter, we develop a novel process to fill the interline space with air (dielectric constant = 1). A silicon wafer, whose face is downward, patterned with metal lines, is placed on the top of another silicon wafer coated with dry polyimide. Hydrogen silsesquioxanes (HSQ), FOx-16, is diluted and trickled through the slit between the metal lines and the polyimide. Then the HSQ forms an ultrathin liquid layer on the dry polyimide and contacts with the top of the metal lines. After the liquid HSQ becomes dry, the air gap is formed, The dry polyimide has good adhesion to silicon substrate but not to the dry FOx-16, so we can separate the polyimide from the dry FOx-16 and get the air gap. The liquid property of HSQ and its high selective adsorption between the metal lines and the polyimide are utilized to form the air gap.
A pretreatment technique to improvement the ashing resistance of low k spin-on-polymer (SOP)
(1999)
Chang, KM
;
Yang, JY
;
Chang, YH
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The oxygen plasma via resists strip process cause significant damage to organic SOP, thus limiting its inter-level dielectric application. A simple treatment technology using reactive ion is proposed to reform the SOP surface. The reactive ion modification of the SOP can improve the resistance towards oxygen plasma. This is owing to the carbon atom absence in the SOP's surface area. The measurements of Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), stress, thickness variation, Scanning Electron Microscope (SEM) cross-sectional view for gap filling and dielectric constant show that SOP with reactive ion treatment (RIT) has better quality for non-etch-back process than SOP without RIT.
Characterization of hydrogen-treated pentacene organic thin film transistors
(2004-04-01)
Yang, JY
;
Suen, SC
;
Whang, WT
;
材料科學與工程學系
;
Department of Materials Science and Engineering
The electrical characteristics of hydrogen-postannealed and hydrogen-plasma-treated pentacene thin film transistors (TFTs) have been investigated. Experimental results have shown that the hydrogen-treated TFTs have improved field-effect mobility and a higher current on/off ratio, compared to untreated devices. The on/off current ratio of the hydrogen-treated devices was markedly increased. However, the TFTs treated with hydrogen plasma have degraded field-effect mobility, compared to hydrogen-postannealed devices.
Dry etching of polysilicon with high selectivity using a chlorine-based plasma in an ECR reactor
(1996-07-01)
Chang, KM
;
Yeh, TH
;
Wang, SW
;
Li, CH
;
Yang, JY
Halogen-bearing gases have proved to be useful plasma discharge etchants for the fabrication of sub-micron poly-Si gate structures. In this paper, investigations of chlorine-based plasmas generated by an electron cyclotron resonance (ECR) reactor for poly-Si etching is studied. The influences of added oxygen, microwave power and RF power on etching characteristics are discussed. In addition, the etching mechanisms of the underlying oxide are developed. Finally, the Cl-2/HBr/O-2 mixed system is examined. The combined plasma exhibits the features of high selectivity, high anisotropy and high etching rate.
Dry etching of polysilicon with high selectivity using a chlorine-based plasma in an ECR reactor
(1996-07-01)
Chang, KM
;
Yeh, TH
;
Wang, SW
;
Li, CH
;
Yang, JY
Halogen-bearing gases have proved to be useful plasma discharge etchants for the fabrication of sub-micron poly-Si gate structures. In this paper, investigations of chlorine-based plasmas generated by an electron cyclotron resonance (ECR) reactor for poly-Si etching is studied. The influences of added oxygen, microwave power and RF power on etching characteristics are discussed. In addition, the etching mechanisms of the underlying oxide are developed. Finally, the Cl-2/HBr/O-2 mixed system is examined. The combined plasma exhibits the features of high selectivity, high anisotropy and high etching rate.
Effect of adding Ar on the thermal stability of chemical vapor deposited fluorinated silicon oxide using an indirect fluorinating precursor
(1997-05-12)
Chang, KM
;
Wang, SW
;
Li, CH
;
Yeh, TH
;
Yang, JY
For a low dielectric constant intermetal dielectric application, fluorinated silicon oxide (FxSiOy) films were deposited in an electron cyclotron resonance chemical vapor deposition system, with SiH4, O-2, and CF4 as the reaction gases. Since the CF4 is an indirect fluorinating precursor, the fluorinating mechanism resembles that of the oxide etching by a fluorocarbon plasma. Thermal stability of the incorporated fluorine (and hence, the dielectric constant) relies heavily on the deposition parameters and technologies. According to experimental results, adding Ar gas during deposition can improve the thermal stability of incorporated fluorine. Such an improvement is due to the fact that Ar sputtering enhances the removal of weakly bonded silicon fluoride on the as-deposited film surface, thereby elevating the mean bonding strength of fluoride remaining in the oxide. (C) 1997 American Institute of Physics.
Effects of gas ratio on electrical properties of electron-cyclotron-resonance nitride films grown at room temperature
(1996-06-01)
Chang, KM
;
Tsai, JY
;
Li, CH
;
Yeh, TH
;
Wang, SW
The effects on the electrical properties of electron-cyclotron-resonance (ECR) nitride films grown at room temperature with different SiH4/N-2 gas ratios from 7 sccm/43 seem to 2 sccm/48 seem are systematically investigated. Superior properties of the films with low bulk trap density 8X10(17) cm(-3), small trap cross section, high breakdown strength 12.12 MV/cm, and near-stoichiometric refractive index 2.0 are obtained when the gas ratio SiH4/N-2 is 5 sccm/45 sccm, the microwave power is 210 W, and the chamber pressure is 0.5 mTorr. With the microwave power, total gas flow rate, and total pressure unchanged, the decrease in SiH4/N-2 ratio lower than 5/45 results in larger trap density and some lower breakdown strength. On the other side, increasing SiH4/N-2 ratio results in higher hydrogen content, lower breakdown strength, and films which are easily degraded during consecutive voltage sweep. High microwave power will eliminate the weak bonds and strengthen the electrical stability of the high SiH4/N-2 ratio film. (C) 1996 American Institute of Physics.
Effects of gas ratio on electrical properties of electron-cyclotron-resonance nitride films grown at room temperature
(1996-06-01)
Chang, KM
;
Tsai, JY
;
Li, CH
;
Yeh, TH
;
Wang, SW
The effects on the electrical properties of electron-cyclotron-resonance (ECR) nitride films grown at room temperature with different SiH4/N-2 gas ratios from 7 sccm/43 seem to 2 sccm/48 seem are systematically investigated. Superior properties of the films with low bulk trap density 8X10(17) cm(-3), small trap cross section, high breakdown strength 12.12 MV/cm, and near-stoichiometric refractive index 2.0 are obtained when the gas ratio SiH4/N-2 is 5 sccm/45 sccm, the microwave power is 210 W, and the chamber pressure is 0.5 mTorr. With the microwave power, total gas flow rate, and total pressure unchanged, the decrease in SiH4/N-2 ratio lower than 5/45 results in larger trap density and some lower breakdown strength. On the other side, increasing SiH4/N-2 ratio results in higher hydrogen content, lower breakdown strength, and films which are easily degraded during consecutive voltage sweep. High microwave power will eliminate the weak bonds and strengthen the electrical stability of the high SiH4/N-2 ratio film. (C) 1996 American Institute of Physics.
Influences of deposition temperature on thermal stability and moisture resistance of chemical vapor deposited fluorinated silicon oxide by using indirect fluorinating precursor
(1996-08-26)
Chang, KM
;
Wang, SW
;
Wu, CJ
;
Yeh, TH
;
Li, CH
In this letter, fluorinated silicon oxide (FxSiOy) films were deposited in the electron cyclotron resonance (ECR) chemical vapor deposition system with SiH4, O-2, and CF4 as the reaction gases. The CF4, in contrast to SiF4 or FSi(OC2H5)(3) used in other reports, is an indirect fluorinating source. The fluorinating mechanism is similar to that of the etching of oxide by fluorocarbon plasma, therefore, the thermal stability of the incorporated fluorine must strongly depend on the deposition temperature. It is found that the thermal stability and moisture resistance are greatly improved by increasing the deposition temperature. However, the higher deposition temperature also results in a higher compressed stress and dielectric constant. Besides, to get the moisture resistance, the deposition temperature must be above 300 degrees C. On the other hand, ECR-SiO2 (without fluorination), even deposited at room temperature, is shown to have a good water resistance. Therefore, by choosing deposition temperature for FxSiOy to have enough thermal tolerance and capping with ECR-SiO2, the moisture resistor is suggested for the inter metal dielectric applications.
Influences of deposition temperature on thermal stability and moisture resistance of chemical vapor deposited fluorinated silicon oxide by using indirect fluorinating precursor
(1996-08-26)
Chang, KM
;
Wang, SW
;
Wu, CJ
;
Yeh, TH
;
Li, CH
In this letter, fluorinated silicon oxide (FxSiOy) films were deposited in the electron cyclotron resonance (ECR) chemical vapor deposition system with SiH4, O-2, and CF4 as the reaction gases. The CF4, in contrast to SiF4 or FSi(OC2H5)(3) used in other reports, is an indirect fluorinating source. The fluorinating mechanism is similar to that of the etching of oxide by fluorocarbon plasma, therefore, the thermal stability of the incorporated fluorine must strongly depend on the deposition temperature. It is found that the thermal stability and moisture resistance are greatly improved by increasing the deposition temperature. However, the higher deposition temperature also results in a higher compressed stress and dielectric constant. Besides, to get the moisture resistance, the deposition temperature must be above 300 degrees C. On the other hand, ECR-SiO2 (without fluorination), even deposited at room temperature, is shown to have a good water resistance. Therefore, by choosing deposition temperature for FxSiOy to have enough thermal tolerance and capping with ECR-SiO2, the moisture resistor is suggested for the inter metal dielectric applications.
Low-pressure crystallization of sol-gel-derived PbZr0.52Ti0.48O3 thin films at low temperature for low-voltage operation
(2003-05-01)
Wang, DY
;
Chien, CH
;
Chang, CY
;
Leu, CC
;
Yang, JY
The properties of sol-gel-derived 120-nm PbZr0.52Ti0.48O3 thin films crystallized in low-pressure O-2 ambient at 500degreesC have been investigated. it is found that PbZr0.52Ti0.48O3 films crystallized in low-pressure oxygen ambient exhibit higher remanent polarization as well as a lower coercive field, compared to those annealed in O-2 atmosphere. The remanent polarization (i.e., 2P(r)) for samples annealed in 60 mbar O-2 ambient is as high as 36 muC/cm(2), and the coercive field (2E(C)) is 99.9 kV/cm at an applied voltage of 2 V. The improvement of P-E hysteresis loops by low-pressure oxygen annealing is ascribed to less incorporation of oxygen and other residues in the resultant PbZr0.52Ti0.48O3 films, since the reductions in the amount of these residual species are beneficial for the complete transformation of the perovskite structure. The reductions in oxygen content and amounts of other residues such as CO2 and H2O are confirmed based on Auger depth profiles and thermal desorption spectra (TDS), respectively.
Metalorganic chemical vapor deposition of tungsten carbonitride films by bis(tertbutylimido)bis(diethylamido)tungsten.
(2002-04-07)
Chuang, SH
;
Chiu, HT
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Chou, YH
;
Chang, YH
;
Chen, SF
New constraint stabilization technique for dynamic systems with nonholonomic constraints
(1999-05-01)
Wu, SD
;
Chiou, JC
;
Yang, JY
;
電控工程研究所
;
Institute of Electrical and Control Engineering
Reactive ion pretreatment technique to improve the ashing resistance of low dielectric constant high carbon content polymer
(2000-07-01)
Chang, KM
;
Yang, JY
;
Chang, YH
;
Tsai, JY
;
電子工程學系及電子研究所
The oxygen plasma via resist strip process causes significant damage to organic spin on polymer (Allied Signal X-720); thus its inter-level dielectric application is limited. A simple treatment technology, reactive glass stabilization (RGS), using reactive ion is proposed to reform the X-720 film surface. The reactive ion modification of the X-720 film can improve the resistance against oxygen plasma. The measurements of stress, thickness variation, scanning electron microscope (SEM) micrographs of gap filling and dielectric constant show that RGS can be practically used in the low dielectric material application with non-etch-back process. The measurements of fourier transform infrared (FTIR) spectroscopy, and auger electron spectroscopy (AES) show that RGS can effectively reform the surface of the X-720 film and increase the ashing resistance even in high carbon content spin on polymer.
Robust attitude control of spacecraft using sliding mode control and productive networks
(1997-05-01)
Chiou, JC
;
Hwang, MC
;
Wu, SD
;
Yang, JY
;
交大名義發表
A new robust attitude control design of spacecraft is proposed by combining sliding mode control (SMC) and productive networks (PN). Essentially, the sliding mode control uses discontinuous control action to drive state trajectories toward a specific hyperplane in the state space, and to maintain the state trajectories sliding on the specific hyperplane. This principle provides a guideline to design a robust controller. Productive networks, which are a special type of artificial neural network, are then used to implement reaching and sliding conditions, and tackle the drawbacks of SMC such as chattering and high control gains. Attractive features of the proposed method include a systematic procedure of controller design, a reduction in chattering, robustness against model uncertainties and external disturbances. An inverted pendulum and a spacecraft attitude control problem are given to deomonstrate the effectiveness of the proposed method.
Robust attitude control of spacecraft using sliding mode control and productive networks
(1997-05-01)
Chiou, JC
;
Hwang, MC
;
Wu, SD
;
Yang, JY
;
電控工程研究所
A new robust attitude control design of spacecraft is proposed by combining sliding mode control (SMC) and productive networks (PN). Essentially, the sliding mode control uses discontinuous control action to drive state trajectories toward a specific hyperplane in the state space, and to maintain the state trajectories sliding on the specific hyperplane. This principle provides a guideline to design a robust controller. Productive networks, which are a special type of artificial neural network, are then used to implement reaching and sliding conditions, and tackle the drawbacks of SMC such as chattering and high control gains. Attractive features of the proposed method include a systematic procedure of controller design, a reduction in chattering, robustness against model uncertainties and external disturbances. An inverted pendulum and a spacecraft attitude control problem are given to deomonstrate the effectiveness of the proposed method.
The influence of precleaning process on the gate oxide film fabricated by electron cyclotron resonance plasma oxidation
(1997-01-01)
Chang, KM
;
Li, CH
;
Fahn, FJ
;
Tsai, JY
;
Yeh, TH
The influence of the precleaning process on the characteristics of SiO2 film grown by using electron cyclotron resonance (ECR) plasma oxidation at room temperature is presented in this work. We find that the growth rate, electrical properties, and reliability of the ECR plasma grown oxide is improved by this precleaning step. Two growth mechanisms are found which determine the electrical properties of the plasma grown oxide. The plasma damage is also discussed. We find that plasma oxidation produces little plasma damage in our experiments. Excellent ECR plasma grown silicon dioxide with good electrical properties and reliability characteristics are obtained by this precleaning technique.