Browsing by Author "Chen, H. -C."

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A Novel Junctionless FinFET Structure with Sub-5nm Shell Doping Profile by Molecular Monolayer Doping and Microwave Annealing
(2014)
Lee, Y. -J.
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Cho, T. -C.
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Kao, K. -H.
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Sung, P. -J.
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Hsueh, F. -K.
For the first time, a novel junctionless (JL) FinFET structure with a shell doping profile (SDP) formed by molecular monolayer doping (MLD) method and microwave annealing (MWA) at low temperature is proposed and studied. Thanks to the ultra thin SDP leading to an easily-depleted channel, the proposed JLFinFET can retain the ideal subthreshold swing (similar to 60 mV/dec) at a high doping level according to simulations. Poly Si based JLFinFETs processed with MLD and MWA exhibit superior subthreshold swing (S.S. similar to 67mV/dec) and excellent on-off ratio (>10(6)) for both n and p channel devices. Threshold voltage (V-TH) variation due to random dopant fluctuation (RDF) is reduced in MLD-JLFinFETs, which can be attributed to the molecule self-limiting property of MLD on the Si surface and quasi-diffusionless MWA at low temperature. Our results reveal the potential of the proposed SDP enabling a JLFET showing reduced variation and outstanding performance for low power applications.
Full Low Temperature Microwave Processed Ge CMOS Achieving Diffusion-Less Junction and Ultrathin 7.5nm Ni Mono-Germanide
(2012-01-01)
Lee, Y. -J.
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Chuang, S. -S.
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Liu, C. -I.
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Hsueh, F. -K.
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Sung, P. -J.
For the first time, Ge CMOS with all thermal processes performed by microwave annealing (MWA) has been realized. The full MWA process is under 390 degrees C. It significantly outperforms conventional rapid thermal annealing (RTA) process in 3 aspects: (1) Diffusion-less junction: for easily diffused n-type dopant, phosphorous (P), the ion implantation dopant profile after the MWA activation process remains unchanged. (2) Increased C-ox and lower gate leakage: the low temperature activation process leads to less Ge out-diffusion during MWA than RTA, suppressing the degradation of gate dielectric/ Ge channel interface. (3) Ultrathin 7.5nm Ni mono-germanide with low sheet resistance (Rs) and contact resistivity: after two-step MWA, a thin mono-NiGe layer was obtained which has larger crystallite size to lower Rs. Ge n- and p-MOSFET were also demonstrated. Compared to conventional RTA, the MWA gives 50% and 24% drive current enhancement for p- and n-MOSFET, respectively. These data show that the low temperature MWA is a very promising thermal process technology for Ge CMOS manufacturing.
Low-speed performance comparisons of back-EMF detection circuits with position-dependent load torque
(2009-03-01)
Chen, H. -C.
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Tsai, T. -Y.
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Huang, C. -K.
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電控工程研究所
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Institute of Electrical and Control Engineering
Because of the widely used brushless DC motors (BDCMs) in high-efficiency variable-speed compressors, many sensorless controls with square-wave operation had been developed in the literatures. Recently, more and more low-production-cost BDCM-type compressors with position-dependent load torque, such as rotary compressors, are applied to the residential products, which lead to the importance of low-speed performance of sensorless control. The authors address the low-speed performance comparisons between two common back-EMF detecting circuits (BEDCs). Without using the actual refrigerant system, a Motor-Generator set coupled with a disk and copper cylinder are also built up to serve as the experimental position-dependent load torque. From the simulated and experimental results, one of the BEDCs is better than the other one for the low-speed application of position-dependent load torque.
Synthesis of porous micro-sized titania cages and their photocatalytic property
(2013-12-16)
Tsai, M. -C.
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Yang, M. -H.
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Chang, Y. -W.
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Tzeng, J. -K.
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Lee, C. -Y.
Micro-sized TiO2 cage consisted of anatase nanopartides on the edges of each cube, was synthesized using TTIP as the reagent and NaF submicrometer sized cubes as the template. When a salt of cube was adopted as the template, the reactants prefer to grow on the active sites, edges and corners of the cube, after removing the NaF template, the skeleton of the cube remain as the cage-shaped materials. The hierarchical structures with nano-sized anatase particles and micro scaled cage architecture markedly enlarge the surface area and enhance the light harvesting by light scattering of TiO2 frame, resulting in great photo-catalytic performance, which leads to the photo-degradation of methylene blue by 40% higher than that was achieved by crushed nanoparticles. (C) 2013 Elsevier B.V. All rights reserved.
Visible colour difference-based quantitative evaluation of colour segmentation
(2006-10-01)
Chen, H. -C.
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Wang, S. -J.
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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
The authors present the use of visible colour difference in a new quantitative evaluation scheme for colour segmentation. To avoid directly evaluating the subjectively perceived quality of colour segmentation, two objective visual quantities, the quantity of missing boundaries and the quantity of fake boundaries, are considered. To explore bow missing boundaries and fake boundaries affect the perceived quality of colour segmentation, a few visual rating experiments are made. On the other hand, to fit for humans' visual perception on colour difference, the visible colour difference is defined. Based on the experiments and the visible colour difference, two measures, named intra-region visual error and inter-region visual error, are designed to estimate the degrees of missing boundaries and fake boundaries, respectively. With these two measures, a complete scheme for the evaluation of colour segmentation is proposed. The simulation results demonstrate that this new scheme may evaluate segmentation results without any ground truth, and could help the automatic selection of parameter settings for a given segmentation algorithm.