Browsing by Author "Yu, Y. C."

Now showing 1 - 8 of 8

A compact biological cell irradiation system with a Van de Graaff accelerator
(2013-11-15)
Cho, I. C.
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Niu, H.
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Chen, C. H.
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Chou, W. T.
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Yu, Y. C.
This report describes the development of a compact microcell irradiation system in the 3 MV MN Van de Graaff accelerator in the Accelerator Laboratory of National Tsing Hua University (NTHU). The main feature of this system is backscattering, a technique whereby a 100 nm gold scattering foil is placed in the center of a scattering chamber, instead of a 90 bending magnet. The incident particles produced by the accelerator bombard the scattering foil and scatter isotropically. A set of micro pinholes was installed above the scattering foil and directed the 90 scattering particles to irradiate the cell target. This innovation simplifies the system design and massively reduces the cost and space requirements for system construction. (C) 2013 Elsevier B.V. All rights reserved.
DNA double-strand breaks induced along the trajectory of particles
(2011-12-15)
Cho, I. C.
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Niu, H.
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Chen, C. H.
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Yu, Y. C.
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Hsu, C. H.
It is well-known that the DNA damage caused by charged particles considerably differs from damage due to electromagnetic radiation. In the case of irradiation by charged particles the DNA lesions are more complex and clustered. Such clustered damage is presumed difficult to be repaired, and is potentially lethal. In this study, we utilize a 90 degrees-scattering system and related imaging techniques to investigate the accumulation of gamma-H2AX along the trajectory of charged particles. By immunostaining the gamma-H2AX protein, optical images of corresponding double strand breaks were observed using a high resolution confocal microscope. We demonstrate the difference in the accumulation of gamma-H2AX from irradiation by 1 MeV protons and that of 150 key X-rays. The acquired images were arranged and reconstructed into a 3D image using ImageJ software. We discovered that the gamma-H2AX foci, following irradiation by protons, have a tendency to extend in the beam direction, while those from X-ray irradiation tend to be smaller and more randomly distributed. These results can be explained by the physical model of energy deposition. Crown Copyright (C) 2011 Published by Elsevier B.V. All rights reserved.
Memory characteristics of Co nanocrystal memory device with HfO(2) as blocking oxide
(2007-03-26)
Yang, F. M.
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Chang, T. C.
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Liu, P. T.
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Yeh, P. H.
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Yu, Y. C.
In this letter, the Co nanocrystals using SiO(2) and HfO(2) as the tunneling and the control dielectric with memory effect has been fabricated. A significant memory effect was observed through the electrical measurements. Under the low voltage operation of 5 V, the memory window was estimated to similar to 1 V. The retention characteristics were tested to be robust. Also, the endurance of the memory device was not degraded up to 10(6) write/erase cycles. The processing of the structure is compatible with the current manufacturing technology of semiconductor industry. (c) 2007 American Institute of Physics.
Memory characteristics of Co nanocrystal memory device with HfO2 as blocking oxide
(2007-03-26)
Yang, F. M.
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Chang, T. C.
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Liu, P. T.
;
Yeh, P. H.
;
Yu, Y. C.
In this letter, the Co nanocrystals using SiO2 and HfO2 as the tunneling and the control dielectric with memory effect has been fabricated. A significant memory effect was observed through the electrical measurements. Under the low voltage operation of 5 V, the memory window was estimated to similar to 1 V. The retention characteristics were tested to be robust. Also, the endurance of the memory device was not degraded up to 10(6) write/erase cycles. The processing of the structure is compatible with the current manufacturing technology of semiconductor industry. (c) 2007 American Institute of Physics.
Nickel nanocrystals with HfO2 blocking oxide for nonvolatile memory application
(2007-05-28)
Yang, F. M.
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Chang, T. C.
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Liu, P. T.
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Chen, U. S.
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Yeh, P. H.
A distributed charge storage with Ni nanocrystals embedded in the SiO2 and HfO2 layer has been fabricated in this study. The mean size and aerial density of the Ni nanocrystals are estimated to be about 5 nm and 3.9x10(12)/cm(2), respectively. The nonvolatile memory device with Ni nanocrystals exhibits 1 V threshold voltage shift under 4 V write operation. The device has a long retention time with a small charge lose rate. Besides, the endurance of the memory device is not degraded up to 10(6) write/erase cycles. (C) 2007 American Institute of Physics.
Nickel silicide nanocrystals embedded in SiO2 and HfO2 for nonvolatile memory application
(2007-12-03)
Yang, F. M.
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Chang, T. C.
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Liu, Po-Tsun
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Yeh, Y. H.
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Yu, Y. C.
In this study, a nonvolatile memory device with NiSi2 nanocrystals embedded in the SiO2 and HfO2 layer has been fabricated. A significant memory effect is observed during the characterization of the electrical properties. When a low operating voltage, 4 V, is applied, a significant threshold voltage shift of 1.3 V, is observed. The processing of this structure is compatible with the current manufacturing technology of semiconductor industry. (C) 2007 Published by Elsevier B.V.
Temperature dependence of the electric and spintronic transport properties of Germanium on glass
(2017-10-15)
Chen, C. H.
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Lee, C. W.
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Yu, Y. C.
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Lee, C. P.
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電子工程學系及電子研究所
We present electrical spin injection and detection in p-type Ge channels using Ni/Al2O3/Ge on glass tunneling contacts. The entire structure is integrated on a glass substrate. We investigate the temperature dependence of the Hanle effect in a composite p-type Ge on glass (GeOG), using three-terminal configuration Hanle measurements; from these measurements, we observe spin accumulation up to room temperature. A spin signal of 0.3 V and a spin lifetime of 34 ps are obtained at room temperature. (C) 2017 Elsevier B.V. All rights reserved.
Using double layer CoSi2 nanocrystals to improve the memory effects of nonvolatile memory devices
(2007-05-21)
Yang, F. M.
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Chang, T. C.
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Liu, P. T.
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Yeh, P. H.
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Chen, U. S.
The nonvolatile memory device with multilayer nanocrystals has advantages such as the memory effects can be increased by the increasing density of the nanocrystals and the whole retention characteristic can be improved. There are much more electrons that can be stored in the double layer than single layer nanocrystal memory device. The double layer CoSi2 nanocrystals have better retention characteristic than the single layer. The good retention characteristic of the double layer device is due to the Coulomb-blockage effects on the top layer nanocrystals from the bottom layer nanocrystals. So, the memory effects of the nonvolatile memory device can be improved by using the double layer nanocrystals. (c) 2007 American Institute of Physics.