Note: Descriptions are shown in the official language in which they were submitted.
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ELECTROMAGNETIC CONTROL OF CHEMICAL CATALYSIS
RELATED APPLICATIONS
[0001] Tlus application claims benefit of and priority to U.S. Provisional
Patent
Application No. 60/529,869, filed December 15, 2003 entitled "Process of
Chemical Vapor
Deposition of Arrayed Nanostructures: Photon-Electron Assisted CVD", herein
incorporated
by reference in its entirety.
[0002] Background
[0003] 1. Field
[0004] The present disclosure is directed to localized heating of micro or
nanostructures
and their associated methods of use and applications. More particularly and in
one aspect,
the teachings disclosed herein also provides very localized heating of
specific nano and micro
structures for the purpose of influencing a catalyzed chemical reaction. In
one aspect
providing heat for a chemical reaction that takes place on and/or adjacent to
a provided
structure or plurality thereof which generate heat as a result of at least a
Photon-Electron
resonance, as taught herein.
[0005] 2. Related Art
[0006] The use of catalysis in large-scale, continuous chemical processes is
well known.
Many catalytic reactions have a temperature threshold. Prior art methods
typically utilize
macroscopic heat sources to provide heat for such reactions and typically
entail gross
convection, gross conduction, or gross radiation. Examples of such macroscopic
heat sources
are heat strips, ovens, lamps, or heated gasses.
[0007] Inherent with the use of such conventional methods of heating, is the
difficulty of
having control of the temperature of a catalyst , the vicinity of the catalyst
and/or the heat
applied, both temporally and spatially. For example, it may be desirable to
have a reaction
take place for a predetermined time that is considerably less than that
determined by the time
constants associated with a surrounding vessel or substrate in which, or
on/adjacent which,
such reactions are to take place, respectively. For example, if one were able
to provide
required heat at very small, particular areas/locations and not heat the
surrounding vessel
and/or chamber and/or substrate, this would allow much greater temporal
control over the
temperatures utilized and of the catalyst, i.e. reaction times could be
significantly shortened
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because the thermal mass of the vessel or substrate can be neglected. It also
may be desirable
to localize the reaction spatially on the order of nanometers andlor microns.
[0008] The heat that is generated when coupling photons to metal nanoparticles
can be
derived as follows: The polarizability, a, of a small metallic sphere of
radius, R, can be
shown to be:
a = 4~csoR3 ~
s+2s",
where so is the free space dielectric constant, s is the dielectric constant
of the particle, and Em
is the dielectric constant of the nanoparticle. A resonance occurs for a time-
varying, spatial
stationary field when the following conditions is met:
[~real (~) + 2.s", ]2 + [~r",g (~)]Z = Minimum.
This condition can be satisfied with noble metals, and corresponding
nanostructures are
known to have strong absorptions related to Photon-Electron resonances in the
visible portion
of spectrum. "U.K. Kreibig and M. Vollmer's , Optical Properties of Metal
Clusters.
Springer-Verlag., New Yorlc, 1995" herein incorporated by reference in its
entirety. Near the
resonant frequency there is nearly an order of magnitude increase in
absorption. If a particles
is completely absorbing at the appropriate resonance frequency, a simple
Stefan-Boltzman
calculation, Power l area - 6~, where 6 is the Stefan-Boltzman constant, can
estimate the
necessary power to achieve a selected particle temperature .
[0009] From the above, it is seen that localized nanoscale reactions are a
desideratum
and further, for associated apparatus, structures, methods and systems that
can be utilized for
and in a variety of applications and fields.
SUMMARY
[0010] According to one aspect of the disclosure, techniques directed to
chemical
processes is provided. Providing micro or nanostructures and their
applications is also
provided. The present invention may be used for other fields and applications
such as life
sciences, chemistry, material sciences, nano technology, electronics and
others.
[0011] In some exemplary implementations, temperature affected chemical
reactions are
facilitated by selected localized heat provided by at least Photon-Electron
interactions,
sometimes also referred to in the literature and lrnown in the art as plasmon
resonance.
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[0012] As but one example and in one implementation, the present disclosure
provides
for Photon-Electron assisted chemical vapor deposition (PACVD) which utilizes
heat
generated by Photon-Electron interactions in nanometer sized structures as the
heat source to
initiate or facilitate catalytic chemical reactions associated with the
deposition of material.
[0013] In some exemplary implementations, a reaction product can simply be a
heated
reactant that is heated by Photon-Electron interactions in accordance with the
teachings of the
present disclosure. A reactant heated in this manner can be utilized in
additional steps/ and or
processes if so desired. In particular and in accordance with teachings
provided herein,
application of particular pre-determined frequencies and/or frequency ranges
of
electromagnetic radiation excite at least a Photon-Electron resonance at the
nanometer sized
structures and controls the heating and relative temperature of nanometer
sized structures by
which chemical reactions occur.
[0014] In some exemplary implementations a laser provides the electromagnetic
radiation utilized to excite at least a Photon-Electron resonance.
[0015] In some exemplary implementations, the present disclosure provides for
the use of
light sources such as a laser source and conventional optics to provide the
desired
electromagnetic radiation which selectively drives the Photon-Electron
resonance to heat the
nanometer sized structures utilizing substantially lower power densities than
are typically
utilized by the prior art to heat material thereby encouraging, facilitation
and/or initiating a
reaction.
[0016] Some exemplary implementations allow for spatial control of chemical
processing, such as chemical synthesis, deposition, and/or degradation upon a
catalytic
substrate on a scale of nanometers. This also provides for a high degree of
temporal control
of the temperature of the processes/reactions. Stopping incident
electromagnetic radiation
flux to the nanometer sized structures results in very rapid lowering of
temperature at the
nanometer sized structures, i.e. a previously established Photon-Electron
resonance of these
structures attenuates/diminishes, as does the associated generated localized
heat.
[0017] Techniques using micro or nanostructures for electromagnetically
controlled
chemical catalysis are provided. More particularly, the teachings disclosed
herein provide
methods, systems, and resulting structures for enhancing chemical reactions
via a catalysis
based on a combination of lcnown catalytic microstructures and
heating/temperature control
based on electromagnetically driven Photon-Electron interactions.
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[0018] In an exemplary implementation, the method includes providing reactant
or
reactants, such as, but not limited to, a reactive species (e.g., Ti (2,2,6,6-
tetramethyl-3,5-
heptanedione, SiH4, and GeH4 adjacent to one or more particles and irradiating
the one or
more particles with electromagnetic radiation (e.g., from a laser source, or
other source)
which has a pre-selected frequency, i.e. substantially matches or matches the
Photon-Electron
resonance frequency or "P-ERF" of the surface electrons of the one or more
structures, here
for example, a particle or plurality of particles. The term "adjacent" is
taken to include actual
contact between one object and another. A reactant can be any element or
compound that can
undergo or be part of a reaction that occurs as a result of exposure to heat
provided by the
excitation of at least Photon-Electron resonance, as disclosed herein.
Increases in
temperature of the one or more particles to at least a selected temperature
(e.g., reaction
temperature) results from an influence of at least the electromagnetic
radiation having the
pre-selected frequency. The method causes a chemical reaction of the reactant
from at least
the increase in the temperature of the one or more particles.
[0019] In an exemplary implementation, the present disclosure provides an
alternative
method for accelerating a catalytic chemical reaction using electromagnetic
radiation. The
method includes providing one or more particles. Preferably, the one or more
particles have
a thermal characteristic. The method includes applying at least one reactant
adjacent and/or
on one or more particles and irradiating the one or more particles with
electromagnetic
radiation which has a pre-selected frequency. The method includes increasing a
temperature
of the one or more particles having the thermal characteristic to at least a
selected
temperature from an influence of at least the electromagnetic radiation having
the pre-
selected frequency and causing a catalytic chemical reaction of the at least
one reactant from
at least the increase in the temperature of the one or more particles. That
heat may be used
for other processes such as to initiate formation of a reaction product.
[0020] In some exemplary implementations, the particles heated through
irradiation and
Photon-Electron interactions can themselves be the catalytic agent in the
enhanced chemical
reaction process. In other exemplary implementations, multiple particles may
be used
together; some of these particles may be used to cause a localized temperature
increase
through the aforementioned Photon-Electron interactions, while others act as
the catalytic
particles, which enhance the desired chemical reaction at a suitable
temperature or
temperature range. The benefits of spatial and temporal control may apply in
one or in both
cases.
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[0021] Still further, the present disclosure provides a method for forming a
reaction
product utilizing heat generated by at least Photon-Electron resonance of
provided structures,
in some implementations, disposed in a particular manner upon a substrate. The
exemplary
method includes providing a substrate comprising a pattern of at least one or
more structures
preferably one or more nanostructures, which is made of a selected material.
The method
includes determining a P-ERF of the selected material of the nanostructure and
exciting at
least portion of the selected material using an electromagnetic source
providing
electromagnetic radiation having a predetermined frequency at or substantially
overlapping
with the P-ERF to cause generation of, and an increase in, thermal energy of
the selected
material. The method includes providing at least one reactant
overlying/adjacent the
substrate and the selected material excited at the P-ERF and causing
production of a desired
reaction product, depending upon at least the provided reactant or reactants.
[0022] Depending upon the implementation, the present disclosure also provides
one or
more of the following exemplary features, which are further described
throughout the present
specification and more particularly below.
[0023] 1. A method using Photon-Electron excitation in metallic nanostructures
as a
means for creating local temperature profiles or inducing localized heating
which is sufficient
to initiate chemical reactions.
[0024] 2. Photon-Electron excitation in metallic nanostructures to locally
heat a
structure , such as a pre-form, in a determined space, according to exemplary
implementations is also disclosed. A brief sequence of steps can be provided
as follows:
a. Developing and/or providing at least one metallic nanostructures upon a
substrate (a pre-form), such as, but not limited to, an array of palladium or
gold
particles by any effective means, including but not limited to electron beam
lithography, precipitation and nano-imprinting.
b. Computing and/or utilizing the P-ERF (e.g., or frequency range) for given
selected material, spacing, particle size, etc of the metallic nanostructures.
c. Using a light source of appropriate frequency and/or frequency range and
sufficient intensity to induce Photon-Electron resonance heating in each of
the at least
one nanostructures. This can be accomplished by using a focused or a diffuse
source
which can excite all metallic nanostructures simultaneously.
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d. Carrying out step (c) inside a determined space so that at least one
reactant
such as, for example, vaporized chemical precursors, is provided and is in
contact
with heated metallic nanostructures, which catalyze a chemical reaction.
[0025] Controlling the electromagnetic radiation source can be used to at
least turn on/off
heating. Heating is induced more rapidly and dissipates more rapidly since it
is the interaction
of incident electromagnetic radiation with the metallic nanostructures that
establishes, via at
least Photon-Electron resonance, localized heating of the metallic structures
and not the
whole of the substrate. Removing the incident electromagnetic radiation flux,
having the
appropriate frequency or range of frequencies, from the metallic structures
results in very fast
cooling of the metallic structures due to the small size/mass of the metallic
structures.
[0026] Depending upon the implementation, one or more of these features may be
included. Of course, one of ordinary slcill in the art would recognize many
variations,
modifications, and alternatives. In particular, it should be clear that varied
types of particles,
nanoparticles or nanostructures could be used in the same process. Some
particles or
nanostructures could be used to control temperature in the manner indicated
above, but not to
have catalytic activity. Other particles could be present on the pre-form
which act as catalysts
when the appropriate temperature is reached.
[0027] Additionally, some exemplary implementations provided herein integrates
with
and provide processes and apparatus that are compatible with conventional
fabrication/process technology without substantial modifications to equipment.
Preferably,
the teachings disclosed herein provide for an improved process integration for
design rules of
nanometers and less. These and other benefits will be described in more
throughout the
present specification and more particularly below.
[0028] In some exemplary implementations, the specific localized heating of
the
structures, such as nanostructures, results from at least the excitation of a
Photon-Electron
resonance. In other implementations, specific localized heating of these
structures occurs as
a result of other effects or combination of effects resulting from impingement
of
electromagnetic radiation onto the structures, resulting in heat generation to
a desired
temperature. Exemplary effects that result in the localized heating of the
present invention
can include excitation of a Photon-Electron resonance, phonon lattice
vibrations, electron
hole creationldynamics and Landau damping, or any combination thereof.
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[0029] In one aspect, the teachings of the present disclosure provide a method
facilitating
chemical reactions utilizing localized heating, comprising the steps of
providing a substrate
having disposed thereon at least one structure, introducing at least one
reactant adjacent the at
least one structure and irradiating the at least one structure with
electromagnetic radiation. In
some implementations, a plurality of structures is provided. The
electromagnetic radiation
has a pre-determined frequency or range of frequencies that is absorbed by the
at least one
structure and preferentially excites at least a Photon-Electron resonance of
the at least one
structure. This provides and generates localized heat, from the at least one
structure and as a
result of at least the Photon-Electron resonance, and raises the temperature
to facilitate at
least one catalytic chemical reaction involving the at least one reactant,
which provides at
least one reaction product.
[0030] In some implementations at least one structure is provided upon said
substrate in a
desired configuration to provide a pre-form, which determines the locality
where the at least
one catalytic chemical reaction takes place. The pre-form can include a
plurality of structures
or one structure, where the at least one structure or plurality has, for
example, a form selected
from the group consisting of a particle, a dot, a sphere, a wire, a line, a
film and any
combination thereof. In some implementations, the particle, dot, sphere, wire,
line, filin and
any combination thereof have nano-scale dimensions (any one or combination of
height,
length, width, diameter, radius, diagonal etc...). In some implementations,
the particle and/or
sphere can have a radius from about .5 to about 500 nanometers, or from about
1 to 100
nanometers.
[0031] In some exemplary implementations, the at least one structure is or
contains at
least one metal. The metal can be one of gold, copper, silver, titanium,
aluminum, nickel,
palladium, platinum, ruthenium, iridium, iron, cobalt, rhodium, osmium , zinc
or any
combination thereof. The at least one metal can act as a catalyst in the at
least one chemical
reaction and/or act as a localized heating source to provide heat at a
reaction temperature. In
some exemplary implementations, the at least one reactant can be a gas, a
liquid, a plasma, a
solid or any combination thereof.
[0032] In some exemplary implementations, the at least one structure is or
contains at
least one element, or combination of elements as found in the Periodic Table
of the elements
or any combination thereof. The at least one structure can act as a catalyst
in the at least one
chemical reaction and/or act as a localized heating source to provide heat at
a chemical
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8
reaction temperature. In some exemplary implementations, the at least one
reactant can be a
gas, a liquid, a plasma, a solid or any combination thereof.
[0033] In some exemplary implementations, the at least one chemical reaction
involving
the least one reactant can be, for example, a decomposition reaction where the
at least one
reaction product is or contains a component of the at least one reactant. In
some
implementations, the at least one reactant is a compound having a particular
ratio of elements,
where the at least one reaction product has the same ratio of elements as the
compound and
the at least one chemical reaction results in a change of at least one
characteristic of the
compound. Exemplary changes include, for example, a re-arrangement of atoms,
change in
bond number, change in bond type, change in bond angle. In some
implementations, the
reaction brings about a change of at least one characteristic resulting in
isomer production of
the at least one reactant. In some implementations, such isomer production can
result in the
production of enantiomers.
[0034] In some exemplary implementations,.the at least one chemical reaction
involving
the least one reactant can be, for example, any of a substitution reaction, an
addition reaction,
an elimination reaction, a condensation reaction or any combination thereof.
In some
implementations, the at least one reactant combines with at least a second
reactant to form a
reaction product.
[0035] The electromagnetic radiation utilized in some implementations is in
the form of a
laser provided by a laser source. Various laser sources and lasers can be
utilized in
accordance with the present disclosure. Electromagnetic radiation, for
example, can be
ultraviolet, visible or infrared radiation or any combination thereof. In some
implementations, provided electromagnetic radiation irradiates at least a
portion of the
substrate.
[0036] In one aspect, the present disclosure provides methods wherein the at
least one
reactant is a carbon containing compound. In certain implementations, at least
a second
reactant is provided, wherein the at least one reactant is a carbon containing
compound and
the second reactant is a hydrogen containing compound
[0037] In some exemplary implementations, the substrate is comprised of
silicon, or
Group III/V materials or silicon on insulator or germanium or quartz or glass
or any
combination thereof.
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[0038] In some exemplary implementations, electromagnetic radiation having the
pre-
determined frequency or range of frequencies is directed upon a plurality of
structures or a
subset of the plurality of structures. The plurality of structures can
comprise at least a first
subset and a second subset of structures, each subset differing in composition
from another
subset. In one implementation, the first subset heats up to a first reaction
temperature that is
a result of the interaction of the provided electromagnetic radiation
irradiation with the first
subset, to drive at least one catalytic chemical reaction. In an additional
exemplary step,
additional electromagnetic radiation is provided, wherein the additional
electromagnetic
radiation has a pre-determined frequency or range of frequencies that differs
from the
electromagnetic radiation previously provided and excites at least a Photon-
Electron
resonance in the second subset of structures and thus provides heat for an
additional reaction.
[0039] The present disclosure also provides methods and apparatus wherein
localized
heat is provided, at least in part, by at least one of phonon lattice
vibrations, electron hole
creation/dynamics, Landau damping, or any combination thereof, in addition to
said Photon-
Electron resonance to provide disclosed heat.
[0040] The present disclosure also provides for exemplary apparatus for Photon-
Electron
assisted deposition. In some exemplary implementations, such apparatus include
a
determined space, at least one inlet in communication with the determined
space for
conducting at least one reactant into the determined space, a substrate having
disposed
thereon at least one structure, the substrate being located within the
determined space. A
source of electromagnetic radiation is also provided, positioned to irradiate
the substrate with
electromagnetic radiation having a pre-determined frequency or range of
frequencies, that is
absorbed by the at least one structure and excites at least a Photon-Electron
resonance of the
at least one structure. In some implementations, the electromagnetic radiation
is provided
such that it irradiates at least a portion of the substrate having the at
least one structure
disposed thereon. This provides localized heat, from the at least one
structure and as a result
of at least Photon-Electron resonance, at a temperature to facilitate at least
one catalytic
chemical reaction involving the at least one reactant. The apparatus further
comprises and at
least one outlet in communication with the determined space. The at least one
outlet can be
for conducting at least one reaction product from the determined space. Some
implementations can include a second inlet in communication with the
determined space
andlor a second outlet from the determined space.
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[0041] In some exemplary implementations of the apparatus, the least one
structure
contains at least one metal such as, but not limited to, any one of gold,
copper, silver,
titanium, aluminum, nickel, palladium, platinum, ruthenium, iridium, iron,
zinc and any
combination thereof. The at least one structure has a form/shape that can be
any one of a
particle, a dot, a sphere, a wire, a line, a film and any combination thereof.
As discussed
above, some implementations of the apparatus utilize at least one structure
having a
shape/form such as a particle, dot, sphere, wire, line, film and any
combination thereof,
having namo-scale dimensions. Exemplary dimensions, such as height, width,
thickness, etc
can be anywhere from .5 to 500 manometers. Some implementations utilize such
structures
having dimensions of 1 to 100 manometers, and still others of 10 to 50
manometers, or
thereabouts or any range therebetween.
[0042] Depending upon the implementation, the at least one metal of the at
least one
structure can be a catalyst in the at least one deposition reaction andfor
acts as a heat source
for the reaction. Exemplary at least one reactant can be any one or any
combination of gas,
liquid, plasma or solid.
[0043] Various additional objects, features and advantages of the present
invention can be
more fully appreciated with reference to the detailed description and
accompanying drawings
that follow.
BRIEF DESCRIPTION OF THE DRAWINGS
[0044] Figure 1 is an illustrative structure and at least one reactant.
[0045] Figure 1A is an illustrative close-up of a surface of a structure,
incident
electromagnetic radiation, exemplary surface electrons of the structure's
surface and at least
one reactant.
[0046] Figure 1B depicts an exemplary first material layer disposed upon the
structure
and a second incident electromagnetic radiation, a second reactant and
exemplary surface
electrons of the deposited exemplary first material layer.
[0047] Figure 1C depicts a second material deposition layer upon the first
material layer.
[0048] Figure 2A is a depiction of an exemplary substrate, plurality of
structures.
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[0049] Figure 2B is a schematic, enlarged view of a structure shown in FIG. 2A
and a
reactant undergoing an exemplary chemical reaction.
[0050] Figure 3A is a depiction of an exemplary substrate, plurality of
structures and two
reactants.
[0051] Figure 3B is a schematic, enlarged view of a structure shown in FIG. 3A
and
another exemplary reaction.
[0052] Figure 4A is a depiction of an exemplary substrate, plurality of
structures and a
reactant.
[0053] Figure 4B is a schematic, enlarged view of a structure shown in FIG. 4A
and
another exemplary reaction.
[0054] Figure 5 is a schematic, enlarged view of another exemplary structure,
heat and
yet another exemplary reaction.
[0055] Figure 6 is a schematic configuration of an exemplary apparatus in
accordance
with teachings disclosed herein.
DETAILED DESCRIPTION OF THE INVENTION
[0056] Descriptions of exemplary implementations are provided and reference
made to
the accompanying figures which form the part thereof, and which are shown by
way of
illustration of exemplary implementation of teachings provided herein. It is
to be understood
that other implementations and application of the teachings provided herein
may be utilized
and structural and functional changes may be made without departing from the
spirit and
scope of the present disclosure. Additionally, the figures are for
illustrative purposes and no
relative or limiting sizes, scales or ratios are intended.
[0057] Techniques directed to micro or nanostructures and their applications
are
provided. More particularly and in one aspect, the teachings disclosed herein
provide
methods, systems and resulting structures and their use for forming nano and
micro structures
using novel deposition techniques useful for a wide variety of applications.
As merely an
example, such deposition techniques can be applied to formation of one or more
films in the
manufacture of electronic devices, such as integrated circuit, memory media,
storage media
both volatile and non-volatile. It would be recognized that the invention has
a much broader
range of applicability. The generation of heat via at least Photon-Electron
resonance
excitation of dissociated surface electrons by incident electromagnetic
radiation of particular
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structures, such as but not limited to particles, rods, wires, spheres and the
lilce, can be
utilized in and for various manufacturing techniques, particularly nano-scale
manufacturing,
chemical processing and other uses where very localized heat generation is
desired.
[0058] In accordance with some implementations, the size of such structures,
which will
provide/generate heat upon exposure to electromagnetic radiation as described
herein and in
accordance with the teachings disclosed, can have dimensions of about .5 to
about 500
nanometers, preferably from about 1 to 100 nanometers, or any specific range
therebetween
where at least a Photon-Electron resonance can be provided that provides heat
at a desired
temperature, such as a reaction temperature.
[0059] In one implementations, a method for fabricating a film of material
using a
Photon-Electron assisted process according to an implementation of the present
invention
may be outlined as follows:
[0060] A substrate having a surface region is provided, onto which is disposed
a metallic
structure, preferable a metallic nanostructure. In this implementation, this
metallic structure
can be one or more particles having a particular thermal characteristic, e.g.
the ability to
provide appropriate Photon-Electron resonance upon exposure to appropriate
electromagnetic
radiation having the appropriate P-ERF or range of P-ERFs. The P-ERF is the
frequency at
which electromagnetic energy from an electromagnetic wave is efficiently
converted into a
collective electron motion in a solid structure. The Photon-Electron resonance
frequency may
be derived by solving Maxwell's equations with the appropriate boundary
conditions or it can
be measured empirically from a reflection or absorption spectrum. The one of
more particles
are disposed on at least a portion of the surface region of the substrate. At
least one reactant
is provided within a vicinity of the one or more particles. The at least one
reactant is
composed of at least one component, although the reactant can include two or
more
components. The one or more particles are irradiated with electromagnetic
radiation having a
pre-selected frequency, in a selected spatial region. The spatial region can
be substantially
defined by the position of the one or more particles upon the substrate. The
impacted spatial
region can also include areas of the substrate upon which the one or more
particles are not
disposed. The spatial region can also include areas less than the areas of the
substrate upon
which the one or more particles is disposed, e.g. irradiation falls upon some
particles but not
others at a given time.
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[0061] The pre-selected frequency of the irradiating electromagnetic radiation
is of a
frequency concordant/substantially concordant with a P-ERF of the disposed
metallic
structure, here the one or more particles. Tl>is results in an increase in
temperature of the one
or more particles having the thermal characteristic to at least a selected
temperature, from an
influence of at least the electromagnetic radiation having the pre-selected
frequency. The
surrounding substrate does not appreciably heat up relative to the one or more
particles
disposed thereon. This very specific and localized heating, due to the Photon-
Electron
resonance occurring as a result of the interaction of the electromagnetic
radiation, of pre-
selected frequency, with the delocalized surface electrons of the one or more
particles,
provides the required energy (i.e. heat) to instigate a chemical reaction,
which includes at
least one reactant, from at least the increase in the temperature of the one
or more particles.
This initiates a reaction which may be used for the formation/deposition of a
film of material
based on the at least one reactant.
[0062] Metallic structure 8 in Figures 1 and lA-1C are depicted as squares
simply for
illustrative purposes and can be any desired shape, as previously disclosed.
Incident
electromagnetic radiation 4 excites a Photon-Electron resonance of metallic
structure 8, for
example in an array on a substrate 2 in a CVD environment, which includes at
least one
reactant such as, but not limited to, a vaporized chemical precursor 6.
[0063] Figures lA-1C are up-close illustrative schematics of the surface of a
structure
from which heat is generated by photon-electron interactions in nanometer
sized structures, in
accordance with the teachings disclosed herein. In Figure 1A and taking as an
example
metallic structure 8, the dissociated surface electrons are depicted as "e ".
Incident
electromagnetic radiation 4 having a frequency that is consonant with the
Photon-Electron
resonance of these surface electrons excites and establishes a Photon-Electron
resonance,
which in turn generates heat to a reaction temperature at which a reaction
between metallic
structure 8 and at least one reactant such as a chemical precursors 6 for
example and/or
between chemical precursors 6 themselves, result in formation of material and
deposition 10.
In some implementations the at least one structure plays the dual role of a
catalyst as well as
heat generator. As taught herein, when heat is localized, so may be the
chemical reaction and
any deposition which may be associated therewith .
[0064] Turning to Figure 1B, material that makes up deposition 10 itself has
dissociated
surface electrons which are here depicted as a . A second incident
electromagnetic radiation
20 and second reactant, such as a second chemical precursor 21, are
introduced. The second
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incident electromagnetic radiation 20 has a frequency that is consonant with
the Photon-
Electron resonance of these surface electrons (e ) and excites and establishes
at least a
second Photon-Electron resonance and associated generated heat. The heating
effects from
photon-electron interactions in nanoparticles is related to the average
kinetic energy of the
conduction electrons, and incident electromagnetic radiation will cause
oscillations of
electrons in the surface region of a metal, thereby increasing the average
kinetic energy. The
kinetic energy of the surface electrons is eventually transferred in a
somewhat random
fashion to electrons interior to the surface, namely bulls electrons. This is
the basis of
radiative heating. If however, the electromagnetic radiation is at or near the
P-ERF , there
will be collective oscillations or a resonance of the surface electrons, and
the heating will be
maximized. As the size of a structures decreases, there is an increase in the
surface-to-
volume, ratio which is proportional to 1/R, where R is the radius of the
particle.
Nanoparticles, in particular, have high surface-to-volume ratios so that there
are a larger
number of surface electrons relative to bulls electrons. It is generally
believed that this
accounts for the efficient heating of nanoparticles by electromagnetic
radiation at the plasmon
resonance frequency. The optimal absorption frequency can depend both on the
shape of
individual nanoparticles as well as the geometric arrangement of a collection
of nanopaxticles
(e.g on a surface). For an individual spherical particle, the calculation of
the absorption
spectrum dates back to the work of Mie in the early part of the last century.
Recent
experimental evidence suggests that this heating process can occur on very
fast time scales.
The heat generated can raise the temperature sufficiently to initiate a
chemical reaction. The
heat may be applied between deposition 10 and second chemical precursor 21
and/or
between second chemical precursors 21 themselves, resulting in a second
material formation
and deposition 18 upon previously provided deposition 10.
[0065] Exemplary metals (which may be used to form metallic structures) such
as, Cu,
Ag, Au, Ni, Pd, Pt, Rh, and Ir, have absorption resonances in the visible
wavelengths due to
disassociated surface electrons lrnown as plasmons. By utilizing at least
Photon-Electron
resonance and associated heating of the metallic nanostructures due to
excitation of these
surface electrons, it is possible, to heat, with the appropriate wavelength
and power of
incident light, nanometer sized structures, i.e. nanostructures, such as but
not limited to
spheres, lines, arrays and rods to temperatures suitable for facilitating
deposition reactions
including but not limited to material growth.
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[0066] In some embodiments, the underlying substrate can be comprised of one
or any
combination of silicon, or Group III/V materials (of the periodic table),
silicon on insulator,
germanium, or quartz or glass. In any of the cases described herein, provided
electromagnetic radiation can be provided at a constant rate and/or pulsed
upon the structures
to generate heat as a result of at least a Photon-Electron interaction with
some components of
the structure or plurality of structures. In some embodiments, those
components are metal
containing nanostructures. Facilitated reactions that provide any number of
types of reaction
products some of which may be deposited upon substrate 2.
[0067] In some implementations, substrate can be comprised of one or any
combination
of silicon, or Group III/V materials (of the periodic table), silicon on
insulator, germanium, or
quartz or glass. In any of the instant cases described herein, provided
electromagnetic
radiation can be provided at a constant rate and/or pulsed upon the structures
to generate heat
as a result of at least a Photon-Electron resonance of the structure or
plurality of structures, in
some implementations metal containing nanostructures.
[0068] Various chemical reactions can take place on and or adjacent the at
least one
structure, or plurality of structures (such as an array, for example).
Furthermore, the at least
one structure which acts as a localized heat source can simultaneously act as
a catalyst in at
least one chemical reaction . As stated previously, the at least one
structure, preferably
contains a metal, such as, but not limited to, gold, copper, silver, titanium,
aluminum, nickel,
palladium, platinum, ruthenium, iridium, iron, cobalt, osmium, zinc, rhodium
or any
combination thereof. In some implementations, a plurality of nanostructe
particles are
provided, at least some acting as only heat sources and some acting as only
catalytic units. In
some implementations where a plurality of structures are provided, at least a
first and second
subset of structures can be provided. The subsets can be comprised of the same
materials and
have differing shapes/forms from one another, disposed upon substrate 2 (e.g.
an array and a
set of wires). Other contemplated implementations include subsets of
structures upon a
substrate which are comprised of differing materials, providing each subset of
structures
particular thermal characteristics, e.g. at least Photon-Electron resonances,
that provide heat
as a result if exposure to particular electromagnetic radiation frequencies or
range of
frequencies that do not excite at least Photon-Electron resonances in the
other subset. This
provides specific heat, by a specific subset, for a specific chemical
reaction, all happening
adjacent the other second subset upon the substrate.
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[0069] The at least one structure can be provided, as mentioned previously, as
a particle,
dot, sphere, wire, line, filin or any combination thereof, having nano-scale
dimensions, that
is, having one or any appropriate combination of height, length, width,
radius, diagonal,
diameter of anywhere from .5 to 500 nanometers, preferably between 1 to 100
nanometers or
any range therebetween and thereabouts.
[0070] Reactants of exemplary chemical reactions provided in accordance with
the
present disclosure can be any one or combination of a gas, liquid, plasma or
solid. Various
types of reactions can be provided in accordance with the present teachings.
An exemplary
reaction can be a decomposition reaction wherein at least one reaction product
is or contains
a component of the at least one reactant. This is exemplified in Figure 2A,
where a plurality
of metallic structures 8 are depicted on substrate 2, being irradiated by
electromagnetic
radiation 4 having the pre-determined frequencies or range of frequencies that
excite at least a
Photon-Electron resonance in each metallic structure 8. Exemplary
decomposition reactant
62 is also provided. Figure 2B is a schematic close-up of a single metallic
structure 8, that is
generating heat, here depicted as a plurality of wavy line 29, at a chemical
reaction
temperature as a result of at least the excited Photon-Electron resonance
provided as a result
of the interaction of metallic structure's 8 Photon-Electron electrons with
electromagnetic
radiation 4 at the appropriate Photon-Electron resonance frequency or range of
frequencies.
This increase in temperature occurs adjacent to, upon, and /or in the local
vicinity of the
catalyst (which may be the metallic structures). Exemplary decomposition
reactant 62
undergoes the decomposition and breaks apart into at least two portions 62A
and 62B,
providing at least one desired reaction product. The exemplary reaction
depicted in Figures
2A and 2B is sometimes referred to as an elimination reaction, wherein a
reactant is
eliminated by breakdown into component parts.
[0071] Another exemplary chemical reaction can be a substitution reaction,
where the
least one reactant reacts with at least a second reactant and substitutes
itself or a portion of
itself in place of a portion of the second reactant an/or adds to the second
reactant to produce
a reaction product. This is exemplified in the schematic of Figure 3A, where
in this
exemplary implementation, a plurality of metallic structures 8 are provided
upon substrate 2.
Appropriate electromagnetic radiation 4 is provided to generate heat from the
plurality of
metallic structures 8 due to at least excitation of a Photon-Electron
resonance in plurality of
metallic structures 8. Here an exemplary first reactant is symbolized as a
connected pair of
triangles 62 and a second exemplary reactant is symbolized as a connected pair
of circles 6.
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As shown in the schematic close-up of Figure 3B , heat 29 provides the desired
reaction
temperature adjacent to, upon, and /or in the local vicinity of the catalyst
(which may be the
metallic structures) and at least one chemical reaction takes place. In this
example, one of the
triangles, which can be a portion of the exemplary first reactant, switches
places with one of
portion of the second reactant to provide at least one reaction product having
a portion of the
first reactant and a portion of the second reactant. In Figure 3B, this is
symbolized as the
connected circle and triangle 64. In another exemplary reaction, wholesale
combination of a
first reactant with at least a second reactant can result in an addition
reaction product. That
is, as exemplarily and symbolically depicted in Figure 5, where a first
reactant, shown as star
82 and a second reactant, shown as circle 83, are added together at the
provided chemical
reaction temperature to form a reaction product that is an additive
combination of the two,
here depicted as a pairing of symbols star 82 and circle 83, to provide
combination addition
reaction product 88.
[0072] In some implementations, the at least one reactant of a provided at
least one
chemical reaction is a starting compound 73 having a particular ratio of
elements, as
exemplified in Figure 4A by a circle, square and triangle, symbolizing an
exemplary starting
compound. As before, appropriate electromagnetic radiation 4 is provided,
appropriate heat
is generated via at least a Photon-Electron resonance of metallic structure 8
to a chemical
reaction temperature and at least one chemical reaction takes place,
exemplified in the
schematic of Figure 4B. Here, the at least one reaction and at least one
reaction product,
indicated as altered compound 79, have the same ratio of elements as starting
compound 73
and the at least one chemical reaction results in a change of at least one
characteristic of
starting compound 73. Exemplary changes include any one of a re-arrangement of
atoms,
change in bond number, change in bond type, change in bond angle, or any
combination
thereof. In some implementations, the at least one reaction brings about a
change of at least
one characteristic of starting compound 73, for example resulting in isomer
production of the
at least one reactant. In some implementations, such isomer production can
result in the
production of enantiomers.
[0073] An exemplary apparatus in accordance with one aspect of the disclosure
is
schematically depicted in Figure 6. In this example, the apparatus includes a
determined
space 1200, at least one inlet 1217 in communication with determined space
1200 for
conducting at least one reactant from at least one reactant supply 1204 into
determined space
1200, a substrate 2 having disposed thereon at least one structure, here an
array 7 comprising
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18
a plurality of a metallic structure 8, for example. Other configurations are
contemplated to be
within the scope and teachings of the present disclosure. Substrate 2 is
located within the
determined space and a source of electromagnetic radiation 1202 is also
provided. The
electromagnetic radiation 1202 source 1202 is positioned to irradiate the
substrate having the
at least one structure disposed thereon and/or a portion thereof, with
electromagnetic
radiation having a pre-determined frequency or range of frequencies that is
absorbed by the at
least one structure, exemplarily shown here as an array 7 having a plurality
of a metallic
structures 8, and exciting at least a Photon-Electron resonance of the
plurality of a metallic
structures 8. In some implementations, the electromagnetic radiation 4 is
provided such that
it irradiates at least a portion of the substrate having the at least one
structure disposed
thereon. This provides localized heat, from the at least one structure and as
a result of at least
a Photon-Electron resonance, at a chemical reaction temperature to facilitate
at least one
chemical reaction involving at least one reactant provided by reactant supply
1204. There is
also provided at least one outlet 1219 in communication determined space 1200.
The at least
one outlet 1219 can be for conducting at least one reaction product from
determined space
1200. Some implementations can include a second inlet 1218 in communication
with
determined space 1200 and a second reactant supply 1206 containing a second
reactant.
Additionally and in this implementation, an additional outlet 1220 can also be
provided, in
fluid communication with determined space 1200 and a analyzing apparatus 1210,
such a gas
chromatograph, for example. Furthermore, a vacuum 1208 can also be provided
and can
function to collect at least one reaction product and/or to pull reaction
products to analyzing
apparatus 1210. Of course, appropriate valves 1205 are exemplarily provided as
shown in
Figure 6. The overall operation of the apparatus and monitoring and control of
reactions in
accordance with the teachings provided herein can be provided by at least one
computer
system 1021, which is in operable communication with various components of the
apparatus
set up, as exemplarily shown in Figure 6. Reactants of reactant supplies 1204
and 1206 can
be provided to determined space 1200 in a desired state, such as a gas,
liquid, solid or plasma,
or any combination thereof.
[0074] In some implementations of the apparatus, the least one structure, here
the
plurality of metallic structures 8, contains at least one metal such as, but
not limited to, any
one of gold, copper, silver, titanium, aluminum, nickel, palladium, platinum,
ruthenium,
rhodium, iridium, iron , zinc and any combination thereof. The at least one
structure has a
form/shape that can be any one of a particle, a dot, a sphere, a wire, a line,
a film and any
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combination thereof, as disclosed previously. As discussed above, some
implementations of
the apparatus utilize at least one structure having a shape/form such as a
particle, dot, sphere,
wire, line, film and any combination thereof, having nanoscale dimensions.
Exemplary
dimensions of such structures, such as height, width thickness, diameter,
length or any
combination thereof, are of about .5 to about 500 nanometers. In some
implementations the
at least one structure has dimensions of about 1 to 100 nanometers, and in
still others, of
about 10 to 50 nanometers. The overall sizes provide for establislnnent and
utilization of at
least a Photon-Electron resonance that provides heat at a desired reaction
temperature.
[0075] Depending upon the implementation, the at least one metal of the at
least one
structure is a catalyst in the at least one chemical reaction and/or acts as a
heat source for the
chemical reaction. Exemplary chemical reaction temperatures can be several
hundred
Celsius ( C ) 60 C to 1200 C and thus localized heating, as disclosed and
provided by the
present teachings can reach such temperatures. In various implementations, by
pulsing a
laser, for example, it is possible to control chemical reaction times and
temperatures.
Exemplary apparatus provided herein can host a variety of chemical reactions
in accordance
with the present disclosure, as discussed above.
[0076] In some implementations, exemplary apparatus includes at least one
electromagnetic radiation source 1202, can be derived from a laser source,
such as, but not
limited to, a solid state laser, a semiconductor diode laser, a helium neon
gas laser, an argon
ion gas laser, a krypton ion gas laser, an xenon ion gas, tunable lasers, and
or lamps.
Preferably, the pre-selected wavelength ranges from about 100 nm to about 10
Vim.
Exemplary electromagnetic radiation 4 provided and utilized by exemplary
apparatus can
include one or any combination of ultraviolet, visible or infrared radiation.
The exemplary
source of electromagnetic radiation provides pulsed electromagnetic radiation
having the pre-
determined frequency or range of frequencies.
[0077] As described above, electromagnetic radiation utilized in accordance
with the
present disclosure can be provided by any number of sources such as a laser
source or lamp,
for example. Electromagnetic radiation 4 can be any one or a combination of
ultraviolet,
visible or infrared electromagnetic radiation.
[0078] While Photon-Electron resonance has been discussed in detail, it is
further
contemplated that various other effects, alone or in any combination, may be
contributing to
the very localized, specific heat generation methodologies discussed above.
These may
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include landau damping, electron hole creation/dynamics as well as phonon
lattice vibrations,
in any combination and contribution.
[0079] It is also understood that the examples and implementations described
herein are
for illustrative purposes only and that various modifications or changes in
light thereof will
be suggested to persons slcilled in the art and are to be included within the
spirit and purview
of this application and scope of the appended claims and combinations thereof.
