Browsing by Author "Chu, CH"

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1.55-mu m and infrared-band photoresponsivity of a Schottky barrier porous silicon photodetector
(2001-02-01)
Lee, MK
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Chu, CH
;
Wang, YH
;
Sze, SM
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電子工程學系及電子研究所
We have investigated the spectral responsivity of porous silicon Schottky barrier photodetectors in the wavelength range 0.4-1.7 mum The photodetectors show strong photoresponsivity in both the visible and the infrared bands, especially at 1.55 mum. The photocurrent can reach 1.8 mA at a reverse bias of 6 V under illumination by a 1.55-mum, 10-mW laser diode. The corresponding quantum efficiency is 14.4%. (C) 2001 Optical Society of America.
A modified morphological corner detector
(1998-03-01)
Lin, RS
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Chu, CH
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Hsueh, YC
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資訊工程學系
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Department of Computer Science
In this paper we propose a modified morphological corner detection method which finds convex and concave significant points using simple integer computation. We use the morphological peak extractor to detect convex corners and use a modified valley extractor to detect concave corners. Moreover, information of the distances between pixels on the boundary segment determined by two contiguous significant points and the chord connecting these two contiguous significant points can be applied to remedy the loosing corner due to the shape of the chosen structuring element. (C) 1998 Elsevier Science B.V. All rights reserved.
A novel leakage current separation technique in a direct Tunneling regime gate oxide SONOS memory cell
(2003)
Chung, SS
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Chiang, PY
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Chou, G
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Huang, CT
;
Chen, P
In this paper, data retention for various top and bottom oxide (tunnel oxide) SONOS cells has been extensively investigated. For the first time, a leakage current separation technique has been developed to distinguish the two leakage current components via thermionic and direct tunneling (DT) in the ONO layer. Results show that the short-term leakage is dominated by the direct tunneling, while the long-term leakage is dominated by the thermionic emission. The direct tunneling through either tunnel or blocking oxide can also be identified experimentally. These results are useful toward an understanding of the scaling of SONOS cell with focus on its reliabilities.
Applications of the Web-based collaborative visualization in distributed product development
(2006-04-01)
Chu, CH
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Cheng, CY
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Wu, CW
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資訊工程學系
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Department of Computer Science
This paper illustrates applications of the Web-based collaborative visualization (WCV) in distributed product development. Three software prototypes were developed using the WCV technologies. The first one enables the end users to configure individual parts of 3D assembly in a regular browser, and thus provides an effective tool to collect the customer's voices in e-commerce. The second system realizes mass customization for car interior design. Online ergonomic evaluation is conducted based on the interactions between a digital human mimicking the user and the design model. Finally, an Internet-based design review system is implemented. It enables synchronous communications between a designer and people involved in the change process with no access to CAD. These prototypes demonstrate the practicality, flexibility, and versatility of the WCV in integration with other proprietary software tools using a variety of platforms like ASP framework, Java-based technology, and Windows C/C++ applications. This work shows that the WCV is an interfacing technology, which facilitates 3D information sharing for most product-centric activities in a simple and cost-effective manner. (c) 2006 Elsevier B.V. All rights reserved.
Computer aided parametric design for 3D tire mold production
(2006-01-01)
Chu, CH
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Song, MC
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Luo, VCS
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資訊工程學系
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Department of Computer Science
This paper presents a parametric design system for 3D tire mold production. Tire grooves commonly used in the current industry are classified according to their modeling procedures, and the design parameters for each groove type are characterized. The result serves as a foundation for standardization of the tire mold design. The presented system simplifies the construction of 3D groove surfaces by reducing the number of interactive modeling operations. The resultant surface model is parameterized, and thus, allows for rapid creation of other grooves with simple design tables. In addition, a set of geometric algorithms is proposed that first detects undesired groove geometries arising in the design process, and then corrects them automatically. In this manner, 3D mold models are created with minimal user interactions. This work is implemented in an integrated CAD/CAM system for actual mold production. Test examples demonstrate that it provides an effective approach to reducing the time yet improving the quality of tire mold development. (c) 2005 Elsevier B.V. All rights reserved.
Controlling the diffusion of implanted boron in Si and silicide by multiple implants
(1998-07-01)
Chu, CH
;
Ho, KJ
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Huang, CT
;
Shvu, SH
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Lei, TF
To form an ultra-shallow p(+)-n junction by direct low energy BF2+ implantation is difficult. The channeling of the baron during implant and the transient enhanced diffusion of boron during annealing prohibit the tight control of the boron profile. Using the germanium preamorphization implant, the channeling probability of the boron is suppressed. However, the thickness of the pre-amorphized layer is crucial in alleviating the transient enhanced diffusion of boron. The excess point defects below the original amorphous/crystalline interface play a key role in enhancing the diffusion of boron. Introducing the carbon into the BF2+ implanted Si, the diffusion of the boron is retarded, Combining with the germanium pre-amorphization implant, low energy BF2+ implant and carbon implant, an ultra-shallow p(+)-n junction with a junction depth of about 70 nm is realized after rapid thermal annealing at 1050 degrees C, 10 s, Using the baron implanted TiSi2 as diffusion source to form an ultra-shallow p(+)-n junction is prohibited by the trapping of boron inside the TiSi2. The fabrication of high quality p(+)-n junction using this technique is difficult to achieve. Incorporation of germanium into the baron containing TiSi2, the diffusion of boron inside the TiSi2 is enhanced. Boron easily out-diffuses from the TiSi2 layer into the Si substrate and forms a high quality p+-n shallow junction. Manipulating the diffusion behavior of implanted boron in the Si and TiSi2 could be achieved by the multiple implants of germanium and carbon. The chemical interaction of co-implanted ions with the boron is the key to control the baron profile inside the silicon. (C) 1998 Elsevier Science S.A. All rights reserved.
Defects in Ge+-preamorphized silicon
(1999-11-15)
Chen, PS
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Hsieh, TE
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Hwang, YC
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Chu, CH
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材料科學與工程學系
This work studied the morphology and annealing behaviors of extended defects in Si subjected to various Ge+ preamorphization and BF2+ implantation conditions. The extended defects formed were near the specimen surface when Ge+ implantation energy and dose amount were low. During subsequent annealing, the end-of-range (EOR) loops were enlarged and then moved out of the specimen. High energy/low dose Ge+ implantation generated a damaged layer which initially transformed into a wide zone containing dislocation loops and rodlike defects in the annealed specimen. As the annealing proceeded, the width of defective zone gradually shrunk so that most of the extended defects could be annihilated by defect rejection/recombination process. In addition to the category II defects found in previous investigations, hairpin dislocations emerged in high energy/high dose Ge+-implanted specimens. In this specimen, rodlike defects and hairpin dislocations could be removed by annealing, while the EOR loops became relatively inert so that their removal would require high temperatures and/or long annealing times. Microwave plasma surface treatment was also carried out to form a nitride layer on specimen surface. Experimental results indicate that in addition to effectively reducing the size of EOR loops, surface nitridation might serve as a vacancy source injecting vacancies into Si to annihilate the interstitials bounded by dislocation loops. Reduction in the defect size was pronounced when bias voltage was added to the plasma process. However, radiation damage might occur with too high of a bias voltage. (C) 1999 American Institute of Physics. [S0021-8979(99)06322-7].
Mechanism of nitrogen coimplant for suppressing boron penetration in p(+)-polycrystalline silicon gate of p metal-oxide semiconductor field effect transistor
(1996-09-16)
Chao, TS
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Liaw, MC
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Chu, CH
;
Chang, CY
;
Chien, CH
The mechanism of the nitrogen co-implant to suppress the boron penetration in p(+)-polycrystalline silicon gate has been investigated. The nitrogen coimplant with the BF, combines with the boron to form a B-N complex which results in a retardation of boron diffusion. It is found that metal-oxide-silicon capacitors with nitrogen implantation show improved electrical properties. (C) 1996 American Institute of Physics.
Mechanism of nitrogen coimplant for suppressing boron penetration in p(+)-polycrystalline silicon gate of p metal-oxide semiconductor field effect transistor
(1996-09-16)
Chao, TS
;
Liaw, MC
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Chu, CH
;
Chang, CY
;
Chien, CH
The mechanism of the nitrogen co-implant to suppress the boron penetration in p(+)-polycrystalline silicon gate has been investigated. The nitrogen coimplant with the BF, combines with the boron to form a B-N complex which results in a retardation of boron diffusion. It is found that metal-oxide-silicon capacitors with nitrogen implantation show improved electrical properties. (C) 1996 American Institute of Physics.
Removal of end-of-range defects in Ge+-pre-amorphized Si by carbon ion implantation
(1999-03-15)
Chen, PS
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Hsieh, TE
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Chu, CH
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材料科學與工程學系
;
Department of Materials Science and Engineering
Carbon ion implantation was employed to annihilate the end-of-range (EOR) defects in Ge+-pre-amorphized Si. Experimental results showed that the efficiency of EOR defect removal depends on the Ge+-pre-amorphization conditions, the location of projected range (R-p) of carbon implant and subsequent annealing conditions. The best defect removal occurred when R-p of carbon implantation was brought close to the amorphous/crystalline (a/c) interface generated by Ge+-pre-amorphization. The higher the annealing temperature, the better the interstitial gettering efficiency of carbon atoms was observed. However, transmission electron microscopy investigation revealed the emergence of hairpin dislocations when dose and accelerating voltage of Ge+ implantation were high. In specimens without carbon implantation, the hairpin dislocations could be readily removed by a 900 degrees C, 30 min anneal. For carbon-implanted specimens, the density of hairpin dislocations increased when R-p of carbon implantation was close to the (a/c) interface. The glide motion of hairpin dislocations was affected by Ge+-pre-amorphization conditions and was inhibited by the SiC complexes formed in the vicinity of dislocations so that they became rather difficult to anneal out of the specimens. (C) 1999 American Institute of Physics. [S0021-8979(99)06306-9].
Solid phase epitaxy for low pressure chemical vapor deposition Si films induced by ion implantation
(1999-09-29)
Chen, PS
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Hsieh, TE
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Chu, CH
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材料科學與工程學系
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Department of Materials Science and Engineering
This work investigated the ion implantation induced solid phase epitaxy (SPE) of Si thin films prepared by low pressure chemical vapor deposition (LPCVD). Previous studies indicate that the residual layer at the interface between the Si thin film and single crystalline substrate is the major obstacle to the SPE process of Si film. In this work, Ge+ and Si+ ion were implanted to completely amorphize the Si film prepared by LPCVD. Ion implantation also mixed the interfacial oxide layer and its effects on subsequent epitaxial growth of Si film subjected to various annealing conditions were discussed as well. In addition, the specimen surface was modified by inductive couple plasma (ICP) process. The ICP modification using nitrogen gas could form a vacancy source on the sample surface to enhance the atomic diffusion rare and change the stress state in the vicinity of surface, thereby accelerating the SPE process. (C) 1999 Elsevier Science S.A. All rights reserved.
Suppression of boron penetration in BF2+-implanted poly-Si gate
(1996-12-01)
Chao, TS
;
Chu, CH
;
Wang, CF
;
Ho, KJ
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Lei, TF
In this paper, a comprehensive study of gate engineering to suppress the penetration of boron in p-type metaloxide-semiconductor held-effect transistor (MOSFET) with the p(+)-poly-Si-gate is reported. Four types of poly-Si gate structure, two types of gate dielectrics were investigated to suppress the boron penetration. Among the different gate structures, the stacked amorphous silicon structure was found to be the most effective way to retard the boron penetration. N2O oxide exhibited a better retarding of the boron diffusion as compared with the O-2 oxide. It was found that a combination of stacked amorphous silicon with N2O oxide is the most effective way to suppress the boron penetration. Thermal stability, oxide integrity, and D-it of this sample are superior to all the other samples.
Suppression of boron penetration in BF2+-implanted poly-Si gate
(1996-12-01)
Chao, TS
;
Chu, CH
;
Wang, CF
;
Ho, KJ
;
Lei, TF
In this paper, a comprehensive study of gate engineering to suppress the penetration of boron in p-type metaloxide-semiconductor held-effect transistor (MOSFET) with the p(+)-poly-Si-gate is reported. Four types of poly-Si gate structure, two types of gate dielectrics were investigated to suppress the boron penetration. Among the different gate structures, the stacked amorphous silicon structure was found to be the most effective way to retard the boron penetration. N2O oxide exhibited a better retarding of the boron diffusion as compared with the O-2 oxide. It was found that a combination of stacked amorphous silicon with N2O oxide is the most effective way to suppress the boron penetration. Thermal stability, oxide integrity, and D-it of this sample are superior to all the other samples.
Suppression of boron penetration in P+-poly-Si gate metal-oxide-semiconductor transistor using nitrogen implantation
(1997-03-01)
Chao, TS
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Chien, CH
;
Hao, CP
;
Liaw, MC
;
Chu, CH
The mechanism and the optimization of nitrogen implantation for suppression the boron penetration in p(+)-poly-Si gate metal-oxide-semiconductor capacitor is reported. This nitrogen co-implantation process exhibits a good suppression of boron penetration and a better electrical characteristic than that of control sample. It was found that nitrogen combines with the boron to form a B-N complex, retarding the penetration of boron itself, was identified by XPS measurements. The optimum nitrogen dosage is also found in this study.
The influence of Ge-implantation on the electrical characteristics of the ultra-shallow junction formed by using silicide as a diffusion source
(1996-03-01)
Huang, CT
;
Lei, TF
;
Chu, CH
;
Shvu, SH
;
電子工程學系及電子研究所
The electrical characteristics of ultra-shallow p(+)/n junctions formed by implanting a 60 keV Ge+ into a TiSi2 layer have been studied. A very low reverse leakage current density (congruent to 0.4 nA/cm(2) at -5 V) and a very good forward ideality factor n (congruent to 1.001) were achieved in these ultra-shallow p(+)/n junctions, From the secondary ion mass spectrometry (SIMS) analysis, the junction depth was measured to be 600 Angstrom and the surface concentration was about 3 times higher than that of the conventional samples.