Browsing by Author "Huang, LY"

Now showing 1 - 4 of 4

A comprehensive study of hot carrier stress-induced drain leakage current degradation in thin-oxide n-MOSFET's
(1999-09-01)
Wang, TH
;
Chiang, LP
;
Zous, NK
;
Hsu, CF
;
Huang, LY
The mechanisms and characteristics of hot carrier stress-induced drain leakage current degradation in thin-oxide n-MOSFET's are investigated. Both interface trap and oxide charge effects are analyzed. Various drain leakage current components at zero V-gs such as drain-to-source subthreshold leakage, band-to-band tunneling current, and interface trap-induced leakage are taken into account, The trap-assisted drain leakage mechanisms include charge sequential tunneling current, thermionic-field emission current,:and Shockley-Read-Hall generation current. The dependence of drain leakage current on supply voltage, temperature, and oxide thickness is characterized. Our result shows that the trap-assisted leakage may become a dominant drain leakage mechanism as supply voltage is reduced. In addition, a strong oxide thickness dependence of drain leakage degradation is observed. In ultra-thin gate oxide (30 Angstrom) n-MOSFET's, drain leakage current degradation is attributed mostly to interface trap creation, while in thicker oxide (53 Angstrom) devices, the drain leakage current exhibits two-stage degradation, a power law degradation rate in the initial stage due to interface trap generation, followed by an accelerated degradation rate in the second stage caused by oxide charge creation.
Freezing phase scheme for fast adaptive control and its application to characterization of femtosecond coherent optical pulses reflected from semiconductor saturable absorber mirrors
(2005-05-01)
Chen, MC
;
Huang, LY
;
Yang, QT
;
Pan, CL
;
光電工程學系
herent control with a femtosecond pulse shaper. The operational principle is based on a concept that the highest peak intensity will correspond to a frozen phase state of all spectral components involved in a coherent optical pulse. Our experimental and theoretical results reveal this new scheme to be fast and immune to the noise and laser power fluctuation. The freezing phase method has been used to investigate three types of semiconductor saturable absorber Bragg reflector (SBR). The optical pulses reflected from the SBR can be distorted in the spectral phase by a minor structural change of the SBR devices and can be clearly resolved with our method. The technique is useful for a variety of applications that require complete-field characterization and adaptive coherent control on the same setup. © 2005 Optical Society of America.
Hemocompatibility and anaphylatoxin formation of protein-immobilizing polyacrylonitrile hemodialysis membrane
(2005-04-01)
Liu, TY
;
Lin, WC
;
Huang, LY
;
Chen, SY
;
Yang, MC
Plasma proteins were covalently immobilized onto polyacrylonitrile (PAN) membrane to evaluate the hemocompatibility and anaphylatoxin formation. This is used as a model to study the effect of protein-adsorption on the blood-contacting response of hemodializing membranes. The proteins used were either platelet-adhesion-promoting collagen (COL) or platelet-adhesion-inhibiting human serum albumin (HSA). The microstructure and characterization of the protein-immobilizing PAN membranes were evaluated by Coomassie dye assay, atomic force microscopy, X-ray photoelectron spectroscopy and water contact angle measurement. PAN-HSA membrane improved not only hemocompatibility including less platelet adhesion, longer blood coagulation times, and higher thrombin inactivity level, but also induced lower complement activation. On the other hand, PAN COL membrane exhibited blood incompatibility, although induced less increase of C3, C4 antigens of serum. Overall results of this study demonstrated that the immobilization of HSA onto the surface of PAN membrane would be beneficial to improve the hemocompatibility and to reduce the anaphylatoxin formation during hemodialysis. (C) 2004 Elsevier Ltd. All rights reserved.
Surface characteristics and hemocompatibility of PAN/PVDF blend membranes
(2005-05-01)
Liu, TY
;
Lin, WC
;
Huang, LY
;
Chen, SY
;
Yang, MC
Polyacrylonitrile (PAN) was blended with polyvinylidine fluoride (PVDF) at various ratios and made into membranes. The hemocompatibility of the resulting membranes was evaluated based on human plasma proteins adsorption, platelet adhesion, thrombus formation, and blood coagulation time. The PAN/PVDF blends exhibited partial miscibility according to the inward shifting of their two glass transition temperatures. The microstructures of blend membranes examined using atomic force microscopy (AFM) indicated that the roughness increased with the PVDF content, and the phase separation was too severe to form a membrane when the PVDF content was more than 30%. The water contact angle of PAN/PVDF blend membranes increased with the PVDF content. By blending with 20wt% apolar PVDF the adsorption of blood proteins could be reduced, and hence the platelet adhesion and thrombus formation was also reduced. However, when the PVDF content was 30 wt%, severe thrombogenicity was observed due probably to the more porous structure of blend membrane. These results demonstrated that the hemocompatibility would be improved for PAN/PVDF blend membranes with appropriate hydrophilicity and roughness. Copyright (c) 2005 John Wiley & Sons, Ltd.