1,720,992 research outputs found
Stable lateral-shearing interferometer for production-line inspection of lenses
No full textA lateral-shearing interferometer specially devised for production-line inspection of lenses is presented. The interferometer is configured with four square prisms whose relative sliding motions readily provide lateral shearing and phase shifting necessary for evaluating the beam wavefront collimated by the lens under test. The prisms are attached face-to-face using immersion oil so that undesirable disturbances from external mechanical vibration and atmospheric turbulence can be minimized in the measurement. Further, a special phase-measuring least-squares algorithm is adopted to compensate the phase-shifting error caused by the thickness variation in the immersion oil holding the prisms. (C) 1997 Society of Photo-Optical Instrumentation Engineers
Lateral-shearing interferometer using square prisms for optical testing of aspheric lenses
No full textWe present a lateral-shearing interferometer specially devised for production-line inspection of aspheric lenses. The interferometer constitutes four right-angle prisms, whose relative sliding motions provide the lateral shearing and phase shifts necessary for measuring the beam wavefront collimated by the lens under test. The prisms are held together face to face using index-matching oil, so environmental disturbances from external vibration and atmospheric turbulence can be minimized. Furthermore, a special phase-measuring algorithm of least-squares type is adopted to compensate for the phase shift error caused by the variation in thickness of the index-matching oil holding the prisms. Experimental results prove that the interferometer provides a measuring reproducibility of the order of one hundredth of the light's wavelength
Characteristics of solid-phase diffused ultra-shallow junction using phosphorus doped silicon oxide films for fabrication of sub-100 nm SOI MOSFET
No full textDoping properties of the solid-phase diffusion method (SPD) for an ultra-shallow junction formation was investigated. Phosphorous doped silicon oxide films was used as the SPD source for the fabrication of sub-100nm SOI MOSFET. It was found that diffusion depth of the phosphorous could be controlled to be below 40 nm with temperatures lower than 925° C. The results shows that the SPD method is superior to the plasma doping method to form damage-free ultra-shallow junctions.
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Defect-free ultra-shallow source/drain extension using spin-on-dopants for deep submicron SOI MOSFET applications
No full textDefect-free ultra-shallow junction (USJ) formation methods were investigated for sub-50-nm gate-length SOI MOSFET applications by using phosphorus solid-phase diffusion (SPD) and plasma doping (PLAD). NMOSFETs with a gate length of 50-nm and n(+)-p junction diodes were successfully fabricated on SOI substrates. Defect-free n(+)-p junctions with extremely shallow junction depth and low sheet resistance were achieved by using SPD. Moreover, the SPD process generated no crystal defects, which are unavoidable in the ion implantation process and are a primary source of junction leakage currents. The electrical characteristics of n(+)-p junction diodes fabricated using SPD were superior to those fabricated using PLAD, and the SOI NMOSFET with its source/drain extension doped by using SPD showed good short-channel performance. These results demonstrate that solid-phase diffusion can be promising candidate for sub-50-nm MOSFET technologies.
Fabrication and process simulation of SOI MOSFETs with a 30-nm gate length
No full textWe have obtained systematic simulation and experimental results for 30-nm-gate-length metal-oxide-semiconductor field-effect transistor (MOSFET) fabricated on ultra-thin silicon-on-insulator (SOI) substrates. The two-dimensional process simulation and the device simulation were carried out to optimize the fabrication process conditions and the device characteristics of 30-nm-gate-length SOI MOSFETs. A new simple source/drain formation technique using the solid-phase diffusion (SPD) method was developed, Based on the simulation results and the SPD ultra-shallow junction formation technique, we successfully fabricated 30-nm-gate-length SOI nMOSFETs. The experimental results for the 30-nm-gate-length SOI nMOSFETs showed good transistor behaviors and superior device scalability.
Ultra shallow and abrupt n(+)-p junction formations on silicon-on-insulator by solid phase diffusion of arsenic from spin-on-dopant for sub 50 nm Si metal-oxide-semiconductor devices
No full textUltra shallow and abrupt n(+)-p junctions were formed on a silicon-on-insulator (SOI) using solid phase diffusion from arsenic-doped spin-on dopant source with various rapid thermal annealing (RTA) conditions. Their doping profiles and electrical characteristics were investigated and compared with those of junctions prepared from phosphorous-doped spin-on-dopant. Analysis of arsenic doped n(+)-p junctions prepared at the drive-in temperature of 950degreesC revealed that the junction depth and junction abruptness are 27 nm and 8.5 nm/dec., respectively. which are superior to phosphorus-doped junctions. Moreover, the SOI n-type metal-oxide-semiconductor field effect transistor (MOSFET) with the gate length of 90 mm which source and drain extensions were doped from arsenic spin-on-dopant had good short channel properties. (C) 2004 Elsevier B.V. All rights reserved.
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