Impact of nonuniform graded dopant profile in polysilicon gate on gate leakage current

In a MOSFET, a nonuniform, graded vertical dopant profile in the polysilicon gate causes a potential drop at the polysilicon/oxide interface. In this paper, the effect of this potential drop on the gate leakage current has been evaluated for the first time. The extent of variations of this affected gate leakage current with gate oxide thickness, gate length, and gate and drain bias conditions have been assessed with device simulation for an nMOS at 0.13 /spl mu/m low-voltage process. The results provide a guideline to the severity of this effect from the point of view of device and circuit operation and standby power consumption.     

Synthesis and modification of a trifunctional epoxy resin with amino-terminated poly(dimethylsiloxane)s for semiconductor encapsulation

A high-performance trifunctional epoxy resin based on the triglycidyl ether of tris (4-hydroxyphenyl)-methane (TETM) was synthesized by the condensation of 4-hydroxybenzaldehyde with phenol followed by epoxidation with epichlorohydrin. The structure of TETM was confirmed by mass spectra, infrared and nuclear magnetic resonance spectroscopy. Amino-terminated poly(dimethylsiloxane)s were used to reduce the stress of the trifunctional epoxy resin cured with phenolic novolac resin for electronic encapsulation application. The dispersed silicone rubbers effectively reduce the stress of cured epoxy resins by reducing the coefficient of thermal expansion and flexural modulus while the glass transition temperature was hardly depressed.     

Growth and optical properties of In x Ga1−x P nanowires synthesized by selective-area epitaxy

Ternary Ⅲ-Ⅴ nanowires (NWs) cover a wide range of wavelengths in the solar spectrum and would greatly benefit from being synthesized as position-controlled arrays for improved vertical yield,reprodudbility,and tunable optical absorption.Here,we report on successful selective-area epitaxy of metal-particle-free vertical InxGa1-xP NW arrays using metal-organic vapor phase epitaxy and detail their optical properties.A systematic growth study establishes the range of suitable growth parameters to obtain uniform NW growth over a large array.The optical properties of the NWs were characterized by room-temperature cathodoluminescence spectroscopy.Tunability of the emission wavelength from 870 nm to approximately 800 nm was achieved.Transmission electron microscopy and energy dispersive X-ray measurements performed on crosssection samples revealed a pure wurtzite crystal structure with very few stacking faults and a slight composition gradient along the NW growth axis.     

2DVTE: A two-directional videotext extractor for rapid and elaborate design

In video indexing and summarization, videotext is the very compact and accurate information. Most videotext detection and extraction methods only deal with the static videotext on video frames. Few methods can handle motion videotext efficiently since motion videotext is hardly extracted well. In this paper, we propose a two-directional videotext extractor, called 2DVTE. It is developed as an integrated system to detect, localize and extract the scrolling videotexts. First, the detection method is carried out by edge information to classify regions into text and non-text regions. Second, referring to the localization on scrolling videotext, we propose the two-dimensional projection profile method with horizontal and vertical edge map information. Considering the characteristics of Chinese text, the vertical edge map is used to localize the possible text region and horizontal edge map is used to refine the text region. Third, the extraction method consists of dual mode adaptive thresholding and multi-seed filling algorithm. In the dual mode adaptive thresholding, it produces the non-rectangle pattern to divide the background and foreground more precisely. Referring to the multi-seed filling algorithm, it is based on the consideration of the minimum and maximum length and four directions of the stroke while the previous method only considers the minimum length and two directions of the stroke. With this multi-seed exploitation on strokes, precise seeds are obtained to produce more sophisticated videotext. Considering high throughput and the low complexity issue, we can achieve a real-time system on detecting, localizing, and extracting the scrolling videotexts with only one frame usage instead of multi-frame integration in other literatures. According to the experiment results on various video sequences, all of the horizontal and vertical scrolling videotexts can be extracted precisely. We also make comparisons with other methods. In our analysis, the performance of our algorithm is superior to other existing methods in speed and quality.     

NearFar: A computer program for nearside-farside decomposition of heavy-ion elastic scattering amplitude

The NearFar program is a package for carrying out an interactive nearside-farside decomposition of heavy-ion elastic scattering amplitude. The program is implemented in Java to perform numerical operations on the nearside and farside angular distributions. It contains a graphical display interface for the numerical results. A test run has been applied to the elastic scattering at Elab=1503 MeV.

Program summary

Title of program: NearFarCatalogue identifier: ADYP_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADYP_v1_0Program obtainable from: CPC Program Library, Queen's University of Belfast, N. IrelandLicensing provisions: noneComputers: designed for any machine capable of running Java, developed on PC-Pentium-4Operating systems under which the program has been tested: Microsoft Windows XP (Home Edition)Program language used: JavaNumber of bits in a word: 64Memory required to execute with typical data: case dependentNo. of lines in distributed program, including test data, etc.: 3484Number of bytes distributed program, including test data, etc.: 142 051Distribution format: tar.gzOther software required: A Java runtime interpreter, or the Java Development Kit, version 5.0Nature of physical problem: Interactive nearside-farside decomposition of heavy-ion elastic scattering amplitude.Method of solution: The user must supply a external data file or PPSM parameters which calculates theoretical values of the quantities to be decomposed.Typical running time: Problem dependent. In a test run, it is about 35 s on a 2.40 GHz Intel P4-processor machine.     

Parametric Studies on the Behavior of Reinforced Soil Retaining Walls under Earthquake Loading

The finite element procedures are extremely useful in gaining insights into the behavior of reinforced soil retaining walls. In this study, a validated finite element procedure was used for conducting a series of parametric studies on the behavior of reinforced soil walls under construction and subject to earthquake loading. The procedure utilized a nonlinear numerical algorithms that incorporated a generalized plasticity soil model and a bounding surface geosynthetic model. The reinforcement layouts, soil properties under monotonic and cyclic loadings, block interaction properties, and earthquake motions were among major variables of investigation. The performance of the wall was presented for the facing deformation and crest surface settlement, lateral earth pressure, tensile force in the reinforcement layers, and acceleration amplification. The effects of soil properties, earthquake motions, and reinforcement layouts are issues of major design concern under earthquake loading. The deformation, reinforcement force, and earth pressure increased drastically under earthquake loading compared to end of construction.     

Effects of annealing on the polymer solar cells based on CdSe-PVK electron acceptor

CdSe-poly(N-vinylcarbazole) (CdSe-PVK) nanocomposite was synthesized and utilized as the electron acceptor in the active layer of polymer solar cells. The photovoltaic properties of the polymer solar cells based on poly(3-hexylthiophene) (P3HT):CdSe-PVK as the active layer were investigated in detail. The effects of annealing temperature (100-200 °C) and time (5-60 min) on the device performance were studied. At annealing temperature of 150 °C for 30 min, the device demonstrated an optimal efficiency of 0.235% under AM 1.5 (100 mW cm⁻²) solar simulated light irradiation. The improved efficiency under the optimal conditions was confirmed by the highest light harvest in UV-vis spectra due to the increased crystallinity of P3HT after thermal annealing. Photoluminescence of these devices also exhibited that the quench effect increases with the increasing of annealing temperature, indicating that the charge separation between electron-donating (P3HT) and electron-accepting (CdSe-PVK) molecules was increased after heat treatment. Atomic force microscopy (AFM) images showed that the phase segregation and 3D interpenetrating networks of P3HT:CdSe-PVK were responsible for the enhancement of the device efficiency.     

Toughening of epoxy thermosets with nano-sized or micron-sized domains of poly(ethylene oxide)-b-poly(butadiene-co-acrylonitrile)-b-poly(ethylene oxide) triblock copolymers synthesized using room temperature ester coupling reaction

Poly(ethylene oxide)-b-poly(butadiene-co-acrylonitrile)-b-poly(ethylene oxide) (PEO-b-PBN-b–PEO) triblock copolymers with three different compositions were synthesized from poly(ethylene glycol) methyl ethers and carboxylic acid-terminated poly(butadiene-co-acrylonitrile) (CTBN) by ester coupling reaction at room temperature. The PEO-b-PBN-b-PEO was incorporated into anhydride cured epoxy thermosets to improve the fracture toughness by the formation of either nano-sized spherical micelles or micron-sized vesicles. The polymer chemical structure was confirmed by Fourier transform infrared spectroscopy, nuclear magnetic resonance, and gel permeation chromatography. The morphology of PEO-b-PBN-b–PEO within the epoxy thermosets was investigated using a transmission electron microscope, an atomic force microscope, and a scanning electron microscope. Also, we conducted impact testing and plane-strain fracture toughness testing to evaluate the fracture toughness in terms of the impact strength and the critical stress intensity factors (K_IC) for the modified epoxy thermosets. The results revealed that all the PEO-b-PBN-b-PEO triblock copolymers are more effective in the toughening of epoxy thermoset compare to CTBN. We found that the 5 wt% PEO-b-PBN-b-PEO modified epoxy thermoset containing micron-sized vesicles exhibited the highest K_IC, which was 3.23 times as high as the K_IC of pristine epoxy thermoset. Besides, the glass transition temperature remained and the tensile modulus did not reduce remarkably when the amount of PEO-b-PBN-b-PEO added into epoxy was 5 wt%.