1,327 research outputs found
Effects of implementation of decaborane ions in silicon
The next generations of Si microelectronic devices will require ultra shallow p-type junctions formed by implantation of B ions with energies below 1 keV, at which available beam currents are severely limited by space charge effects. To solve this problem, decaborane (B10H14) cluster ion implantation has been suggested as an attractive alternative to conventional B implants, because one decaborane ion implants ten B atoms simultaneously and each of the B atoms only carries approximately 1/11 of the total ion energy. Thus the same implantation depth and dose as with monomer B ions can be obtained using decaborane ions but with 10 times less charge and ten times higher energy. In this dissertation research, various effects of implantation of decaborane cluster ions in silicon were studied, using an experimental ion implanter in the Ion Beam and Thin Film Research Laboratory at NJIT.
Secondary Ion Mass Spectrometry (SIMS) depth profiles of boron and hydrogen in decaborane-implanted samples were measured before and after thermal activation annealing and compared to that in the control samples. Shallow p-type junction could be achieved with decaborane implantation. The co-implanted hydrogen diffused out almost entirely after annealing and hence is expected to have a negligible effect on the device performance.
Transient enhanced diffusion (TED) of B atoms in Si implanted with mass analyzed decaborane ions of three energies were measured and compared to that of B atoms in Si implanted with B+ ions of equivalent B energy and dose. The resultsdemonstrated that implantation of B with decaborane cluster ions led to essentially the same amount of TED of B in Si as that in Si implanted with atomic B+ ions of the equivalent energy and dose.
The sputtering yields of Si with B in the form of decaborane clusters were measured and compared to those for boron monomer ions, estimated using an empirical formula. The surface morphology of amorphous Si, crystalline Si and Ta film irradiated with energetic decaborane ions and argon ions were studied using Atomic Force Microscopy (AFM). Results of surface roughness and Power Spectral Density (PSD) analysis show that decaborane cluster ions smooth rather than roughen these surfaces.
Molecular Dynamics (MD) simulations have been performed to compare impact effects on Si target by B monomers and B10 clusters at the same energy per B atom. B depth profiles were found to be similar for B atoms implanted with B10 clusters and with B monomers. The crater formation, a unique feature of cluster impacts, was also observed on the Si surface impacted by a B10 cluster. The calculated sputtering yield of Si (the number of ejected Si atoms per incident B) was much larger with B10 clusters than with B monomers and also larger than the experimental values.
The results of this research confirm that decaborane implantation is a viable alternative to low energy B implantation for ultra shallow p-type junction formation. These results also contribute to the knowledge base of the technology of ultra shallow B doping in CMOS devices and will help to better understand cluster-solid interactions in general
The Land Experiments in Colour Vision - Colour as a Physical, Phenomenological and Synthetic Object
This thesis analyses the historical and intellectual context of Edwin Land’s experiments in colour vision. I argue that the colour vision research program and retinex theory developed by Land and his colleagues provided a satisfying synthesis of two divergent schools in the history of colour science.
The first chapter of this thesis establishes the existence of the “physical” school of colour science. The defining feature of this school was the belief in the colour atomism hypothesis. This is the idea that the colour perceived at a point in the visual field is completely determined by the physical properties of the light rays entering the retina at that point. In other words, there is a one-to-one correspondence between the physical properties of light rays and colour sensation at a point in the visual field.
The second chapter establishes the existence of the “phenomenological” school of colour science. The defining feature of this school was the discovery of colour phenomena which could not be accounted for by the colour atomism hypothesis. Among these phenomena were “coloured shadows”, “simultaneous colour contrast”, and “colour constancy”.
The third chapter shows how Land’s colour vision research program and retinex theory reconciled these two schools. Land and his colleagues demonstrated that the colour atomism hypothesis is a special case, valid only for points of light. The colour phenomena studied by the “phenomenological” school could be predicted by a computational model – retinex theory – which accounted for colour as it is perceived over a wide visual field, rather than simply at single points. In this process, Land and colleagues built up a new understanding of colour vision as a practical utility evolved for the organism, designed to achieve colour constancy
Teacher roles during amusement park visits – insights from observations, interviews and questionnaires
Amusement parks offer rich possibilities for physics learning, through observations and experiments that illustrate important physical principles and often involve the whole body. Amusement parks are also among the most popular school excursions, but very often the learning possibilities are underused. In this work we have studied different teacher roles and discuss how universities, parks or event managers can encourage and support teachers and schools in their efforts to make amusement park visits true learning experiences for their students
Director's discretionary fund report for FY 1991
The Director's Discretionary Fund (DDF) at the Ames Research Center was established to fund innovative, high-risk projects in basic research which would otherwise be difficult to initiate, but which are essential to our future programs. Here, summaries are given of individual projects within this program. Topics covered include scheduling electric power for the Ames Research Center, the feasibility of light emitting diode arrays as a lighting source for plant growth chambers in space, plasma spraying of nonoxide coatings using a constricted arcjet, and the characterization of vortex impingement footprint using non-intrusive measurement techniques
Quantum Theory at the Crossroads: Reconsidering the 1927 Solvay Conference
We reconsider the crucial 1927 Solvay conference in the context of current
research in the foundations of quantum theory. Contrary to folklore, the
interpretation question was not settled at this conference and no consensus was
reached; instead, a range of sharply conflicting views were presented and
extensively discussed. Today, there is no longer an established or dominant
interpretation of quantum theory, so it is important to re-evaluate the
historical sources and keep the interpretation debate open. In this spirit, we
provide a complete English translation of the original proceedings (lectures
and discussions), and give background essays on the three main interpretations
presented: de Broglie's pilot-wave theory, Born and Heisenberg's quantum
mechanics, and Schroedinger's wave mechanics. We provide an extensive analysis
of the lectures and discussions that took place, in the light of current
debates about the meaning of quantum theory. The proceedings contain much
unexpected material, including extensive discussions of de Broglie's pilot-wave
theory (which de Broglie presented for a many-body system), and a "quantum
mechanics" apparently lacking in wave function collapse or fundamental time
evolution. We hope that the book will contribute to the ongoing revival of
research in quantum foundations, as well as stimulate a reconsideration of the
historical development of quantum physics. A more detailed description of the
book may be found in the Preface. (Copyright by Cambridge University Press
(ISBN: 9780521814218).)Comment: 553 pages, 33 figures. Draft of a book (as of Sept. 2006, same as
v1). Published in Oct. 2009, with corrections and an appendix, by Cambridge
University Press (available at
http://www.cambridge.org/catalogue/catalogue.asp?isbn=9780521814218
PHILOSOPHIES OF COLOUR: GENDER AND ACCULTURATION
Merged with duplicate record 10026.1/658 on 06.20.2017 by CS (TIS)My hypothesis is that 'Colour' as idea acts as a dynamic in the production of
meaning and as such is part of what Le Doeuff (1991: 46-49) argues are deeply held
epistemes that structure and govern our ways of thinking. I have dealt with the
difficulties attendant on the analysis of a phenomenon as insubstantial as colour (as
idea and as precept) by assuming Goethe's (1810: 305-323) concept of the
enrobement of colour to objects without also attaching Goethe's theoretical
hypothesis of moral associations to colour. Thus I combine four different
methodologies to broadly related areas and cloak each in colour: the long cultural
historical view, the statistical, a case study and an applied art historical comparison.
In the first part I have constructed an alternative vision of the development of colour
theory from Plato to now, its philosophical, psychological and mythological
construction and the consequent framing of women as colour. I discuss how a
constructed hierarchy of chromatic value has informed perceptions of gender,
arguing that authoritative epistemologies such as colour theory have established
fallacious belief systems of chromatic value that reinforce cultural perceptions of
gender. In the second I have conducted a three-year perceptual psychology
experiment designed to reveal the extent of stereotyped chromatic perceptions of
gender in visual arts students at two institutions of Higher Education. The data and
results are statistically analysed and the evidence of acculturated chromatic
perception is discussed in relation to universal culturally patterned belief systems of
chroma and gender. Thirdly I have taken 'yellow' as an epistemological and
historical study that proposes and explores an underlying determined semiotic
chroma that ensures normalising belief systems survive material and social change. I
deconstruct some of the theological mythologising structures and meanings of
'Yellow' and discuss the implications for art history of racism and the recuperation
of feminised colour as an adjunct of the phallus. Finally I discuss two women artists,
Sonia Delaunay and Bridget Riley and the implications of the word 'colourist' for
them as women in art practice. I argue that the general unconscious assumption is
that colour originates in emotion instinct and ethnicity and equates women with
colour at the level of the imaginary insisting that success for women artists is
incumbent upon their colour being confined in a phallic symbolic framework of
masculinity. I evidence how acculturated perceptions of 'woman' as colour
naturalises and ensures the continuation and institutionalisation of cultural and
social systems
THE DEVELOPMENT OF A NOVEL ELECTRO-MAGNETIC FORCE MICROSCOPE
This thesis describes the development of a new type of Magnetic Force Microscope
(MFM) probe based on a unique electromagnetic design. In addition the design,
construction and testing of a new MFM system, complete in both hardware and software, is
also described. The MFM allowed initial tests on prototypes of the new probe, and is to
provide a base for future new probe integration. The microscope uses standard MFM
micro-cantilever probes in static modes of imaging. A new computer hosted DSP control
system, software, and its various interfaces with the MFM have been integrated into the
system. The system has been tested using standard probes with various specimens and
satisfactory results have been produced.
A novel probe has been designed to replace the standard MFM magnetic coated tip with a
field generated about a sub-micron aperture in a conducting film. The field from the new
probe is modelled and its imaging capability investigated, with iterative designs analysed
in this way. The practical construction and potential problems therein, of the probe are
also considered. Test apertures have been manufactured, and an image of the field
produced when operating is provided as support to the theoretical designs. Future methods
of using the new probe are also discussed, including the examination of the probe as a
magnetic write mechanism.
This probe, integrated into the MFM, can provide a new method of microscopic magnetic
imaging, and in addition opens a new potential method of magnetic storage that will
require further research
Toward commercial realisation of whole field interferometric analysis
The objective of this work was to produce an instrument which could
undertake wholefield inspection and displacement measurement utilising a
non-contacting technology. The instrument has been designed to permit
operation by engineers not necessarily familiar with the underlying
technology and produce results in a meaningful form. Of the possible
techniques considered Holographic Interferometry was originally identified
as meeting these objectives. Experimental work undertaken 'provides' data
which confirms the potential of the technique for solving problems but
also highlights some difficulties.
In order to perform a complete three dimensional displacement analysis a
number of holographic views must be recorded. Considerable effort is
required to extract quantitative data from the holograms. Error analysis
of the experimental arrangement has highlighted a number of practical
restrictions which lead to data uncertainties. Qualitative analysis of
engineering components using Holographic Interferometry has been
successfully undertaken and results in useful analytical data which is
used in three different engineering design programmes. Unfortunately,
attempts to quantify the data to provide strain values relies upon double
differentiation of the fringe field, a process that is highly sensitive to
fringe position errors. In spite of this, these experiments provided the
confidence that optical interferometry is able to produce data of suitable
displacement sensitivity, with results acceptable to other engineers.....
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