| What is claimed is:
1. An array of ultra-small structures on a surface, comprising:
a substrate;
at least first and second ultra-small resonant structures formed on the
substrate with the first and second ultra-small resonant structures each
producing a different frequency output;
a conductive layer positioned beneath each of the ultra-small resonant
structures; and
a source of a beam of charged particles directed toward the at least
first and second ultra-small resonant structures so that each ultra-small
resonant structure resonates at its desired frequency.
2. The array as in claim 1 wherein said ultra-small resonant
structures are comprised of a material selected from the group consisting
silver (Ag) 5 nickel (Ni), copper (Cu); aluminum (Al), gold (Au) and
platinum (Pt).
3. The array as in claim 1 further including a plurality of each of
the first and second ultra-small resonant structures, with the plurality of the first and second ultra-small resonant structures being space apart from each
other.
4. The array as in claim 1 wherein said first and second ultra-small
resonant structures are formed by an electroplating process.
5. The array as in claim 1 wherein said first and second ultra-small
resonant structures are formed by coating and etching techniques.
6. The array as in claim 1 wherein a conductive material extends
between each of the ultra-small resonant structures
7. The array as in claim 3 wherein the plurality of first and second
ultra-small resonant structures are formed in respective rows.
8. The array as in claim 7 wherein the rows are straight.
9. The array as in claim 1 further including a plurality of rows
comprised of a plurality of spaced apart ultra-small resonant structures, with
the ultra-small resonant structures being formed on a single conductive layer, and with each row within the plurality of rows producing a different
frequency output when energized by the beam of charged particles.
10. The array as in claim 9 wherein the substrate comprises a chip.
11. The array as in claim 9 wherein further including a deflector to
control the beam of charged particles relative to the plurality of rows. |
SINGLE LAYER CONSTRUCTION FOR ULTRA SMALL
DEVICES
Copyright Notice
[0001] A portion of the disclosure of this patent document contains
material which is subject to copyright or mask work protection. The
copyright or mask work owner has no objection to the facsimile
reproduction by anyone of the patent document or the patent disclosure, as it
appears in the Patent and Trademark Office patent file or records, but
otherwise reserves all copyright or mask work rights whatsoever.
CROSS-REFERENCE TO CO-PENDING APPLICATIONS
[0002] The present invention is related to the following co-pending U.S. Patent
applications: (1) U.S. Patent Application No. 11/238,991 [atty. docket 2549-
0003], filed September 30, 2005, entitled "Ultra-Small Resonating Charged
Particle Beam Modulator"; (2) U.S. Patent Application No. 10/917,511 [atty.
docket 2549-0002], filed on August 13, 2004, entitled "Patterning Thin Metal Film
by Dry Reactive Ion Etching"; (3) U.S. Application No. 11/203,407 [atty. docket
2549-0040], filed on August 15, 2005, entitled "Method Of Patterning Ultra-Small
Structures"; (4) U.S. Application No. 11/243,476 [Atty. Docket 2549-0058], filed
on October 5, 2005, entitled "Structures And Methods For Coupling Energy From
An Electromagnetic Wave"; (5) U.S. Application No. 11/243,477 [Atty. Docket
2549-0059], filed on October 5, 2005, entitled "Electron beam induced
resonance,", (6) U.S. Application No. 11/325,432 [Atty. Docket 2549-0021],
entitled "Resonant Structure-Based Display," filed on January 5, 2006; (7) U.S.
Application No. 11/325,571 [Atty. Docket 2549-0063], entitled "Switching Micro-
Resonant Structures By Modulating A Beam Of Charged Particles," filed on
January 5, 2006; (8) U.S. Application No. 11/325,534 [Atty. Docket 2549-0081],
entitled "Switching Micro-Resonant Structures Using At Least One Director,"
filed on January 5, 2006; (9) U.S. Application No. 11/350,812 [Atty. Docket 2549-
0055], entitled "Conductive Polymers for the Electroplating", filed on February
10, 2006; (10) U.S. Application No. 11/302,471 [Atty. Docket 2549-0056],
entitled "Coupled Nano-Resonating Energy Emitting Structures," filed on
December 14, 2005; (11) U.S. Application No. 11/325,448 [Atty. Docket 2549-
0060], entitled "Selectable Frequency Light Emitter", filed on January 5, 2006;
and (12) U.S. Application No. I [Atty. Docket 2549-0086], entitled
"Method For Coupling Out OfA Magnetic Device", filed on even date herewith,
which are all commonly owned with the present application, the entire contents of
each of which are incorporated herein by reference.
Field Of The Disclosure
[0003] This disclosure relates to producing and using ultra-small metal
structures formed by using a combination of various coating, etching and
electroplating processing techniques and accomplishing these processing
techniques using a single conductive layer, and to the formation of ultra
small structures on a substrate that can resonate at two or more different
frequencies on the single layer. The frequencies can vary between micro¬
wave and ultra-violet electromagnetic radiation, and preferably will produce
visible light in two or more different frequencies or colors that can then be
used for a variety of purposes including data exchange and the production of
useful light.
Introduction and summary
[0004] hi its broadest form, the process disclosed herein produces ultra-
small structures with a range of sizes described as micro- or nano- sized.
The processing begins with a non-conductive substrates (e.g., glass, oxidized
silicon, plastics and many others) or a semi-conductive substrate (e.g., doped
silicon, compound semiconductor materials (GaAs, InP, GaN,..)), or a
conductive substrate. The optimal next step can be the coating or formation
of a thin layer of nickel followed by the coating or formation of a thin layer
of silver on the nickel layer. Then a single layer of a conductive material,
such as silver, gold, nickel, aluminum, or other conductive material is then
applied, deposited, coated or otherwise provided on the thin silver layer, and
the conductive layer is then etched or patterned into the desired ultra-small
shaped devices, or the substrate, on which the thin nickel and silver layers
had been coated, is provided with a mask layer which is patterned and then a
conductive material is deposited, plated or otherwise applied. Thereafter,
the mask layer can be removed, although in some instances that may not be
necessary.
[0005] Electroplating is well known and is fully described in the above
referenced '407 application. For present purposes, electroplating is the
preferred process to employ in the construction of ultra-small resonant
structures.
[0006] An etching could also be used, for example by use of chemical
etching or Reactive Ion Etching (RIE) techniques,, as are described in the
above mentioned '511 application, to develop a final pattern in the
conductive layer.
[0007] Where a photoresist material is first applied to the substrate, and
patterned, then a coating or plating process as is explained in the above
mentioned '407 application could be used. In that case, the patterned base
structure will be positioned in an electroplating bath and a desired metal will
be deposited into the holes formed in the mask or protective layer exposed
by one or more of the prior etching processing steps. Thereafter, the mask or
photoresist layer can be removed leaving formed metal structures on the
substrate exhibiting an ultra small size, or alternatively the PR layer will be
removed leaving the formed metal structures lying directly on the substrate.
[0008] Ultra-small structures encompass a range of structure sizes
sometimes described as micro- or nano-sized. Objects with dimensions
measured in ones, tens or hundreds of microns are described as micro-sized.
Objects with dimensions measured in ones, tens or hundreds of nanometers
or less are commonly designated nano-sized. Ultra-small hereinafter refers
to structures and features ranging in size from hundreds of microns in size to
ones of nanometers in size.
GLOSSARY
[0009] As used throughout this document:
[0010] The phrase "ultra-small resonant structure" shall mean any structure of
any material, type or microscopic size that by its characteristics causes electrons to
resonate at a frequency in excess of the microwave frequency.
[0011] The term "ultra-small" within the phrase "ultra-small resonant structure"
shall mean microscopic structural dimensions and shall include so-called "micro"
structures, "nano" structures, or any other very small structures that will produce
resonance at frequencies in excess of microwave frequencies.
Brief Description Of Figures
[0012] The invention is better understood by reading the following detailed
description with reference to the accompanying drawings in which:
[0013] FIG. 1 is a schematic diagram of a first example and embodiment
of the present invention;
[0014] Fig. 2 is a graph showing intensity versus post or finger length for
the series of rows of ultra small structures;
[0015] Fig. 3 is a perspective view of another embodiment of the present
invention;
[0016] Fig. 4 is a view of another embodiment of the present invention;
[0017] Fig. 5 is a graph showing an example of intensity and wavelength
versus finger or post length for a series of ultra small structures;
[0018] Fig. 6 an example of another embodiment of the present invention;
and
[0019] Fig. 7 is another embodiment of the present invention.
Description Of The Presently Preferred Exemplary Embodiments Of
The Invention
[0020] As shown in Figure 1, a single layer of metal, such as silver or other thin
metal, is produced with the desired pattern or otherwise processed to create a
number of individual resonant structures to form a resonant element 14. Although
sometimes referred to herein as a "layer" of metal, the metal need not be a
contiguous layer, but can be a series of structures or, for example, posts or fingers
15 that are individually present on a substrate 13 (such as a semiconductor
substrate or a circuit board) and area designated as 15A, 15b, 15n..
[0021] When forming the posts 15, while the posts 15 can be isolated from each
other, there is no need to remove the metal between posts or fingers 15 all the way
down to the substrate level, nor does the plating have to place the metal posts
directly on the substrate, but rather they can be formed on the thin silver layer or
the silver/nickel layer referenced above which has been formed on top of the
substrate, for example. That is, the posts or fingers 15 may be etched or plated in
a manner so a layer of conductor remains beneath, between and connecting the
posts. Alternatively, the posts or fingers can be conductively isolated from each
other by removing the entire metal layer between the posts, or by not even using a
conductive layer under the posts or fingers. In one embodiment, the metal can be
silver, although all other conductors and conductive materials, and even
dielectrics, are envisioned as well.
[0022] A charged particle beam, such as an electron beam 12 produced by an
electron microscope, cathode, or any other electron source 10, that is controlled by
applying a signal on a data input line 11. The source 10 can be any desired source
of charged particles such as an electron gun, a cathode, an electron source from a
scanning electron microscope, etc. The passing of such an electron beam 12
closely by a series of appropriately-sized resonant structures 15, causes the
electrons in the structures to resonate and produce visible light or other EMR 16,
including, for example, infrared light, visible light or ultraviolet light or any other
electromagnetic radiation at a wide range of frequencies, and often at a frequency
higher than that of microwaves. In Figure 1, resonance occurs within the metal
posts 15 and in the spaces between the metal posts 15 on a substrate 13 and with
the passing electron beam. The metal posts 15 include individual post members
15a, 15b, ...15n. The number of post members 15a...15n can be as few as one and
as many as the available real estate permits. We note that theoretically the present
resonance effect can occur in as few as only a single post, but from our practical
laboratory experience, we have not measured radiation from either a one post or
two post structures. That is, more than two posts have been used to create
measurable radiation using current instrumentation.
[0023] The spaces between the post members 15a, 15b, ...15n (Figure 1) create
individual cavities. The post members and/or cavities resonate when the electron
beam 12 passes by them. By choosing different geometries of the posts and
resonant cavities, and the energy (velocity) of the electron beam, one can produce
visible light (or non- visible EMR) 16 of a variety of different frequencies
including, for example, a variety of different colors in the case of visible
emissions, from just a single patterned metal layer.
[0024] That resonance is occurring can be seen in Figure 2. There, the average
results of a set of experiments in which the radiation intensity from an example of
the present invention was plotted (in the y-axis, labeled "counts" of photons, and
measured by a photo multiplier tube as detected current pulses) versus the length
of the fingers or posts 15 that are resonating (in the x-axis, labeled as "finger
length"). The intensity versus finger or post length average plot shows two peaks
(and in some experimental results with more intense outputs, a third peak was
perhaps, though not conclusively, present) of radiation intensity at particular finger
lengths. For additional discussion, reference can be made to U.S. Application No.
11/243,477, previously referenced above, and which is, in its entirety,
incorporated herein by reference. We conclude that certain finger lengths produce
more intensity at certain multiple lengths due to the resonance effect occurring
within the posts 15.
[0025] Exemplary resonant structures are illustrated in several copending
applications, including U.S. Application No. 11/325,432, noted above and is, in its
entirety, incorporated herein by reference. As shown in Figure 1, the resonant
element 14 is comprised ' a series of posts or fingers 15 which are separated by a
spacing 18 measured as the beginning of one finger 15a to the beginning of an
adjacent finger 15b. Each post 15 also has a thickness that takes up a portion of
the spacing between posts 15. The posts 15 also have a length 125 and a height
(not shown). As illustrated, the posts of Figure 1 are perpendicular to the beam
12. As demonstrated in the above co-pending application, the resonant structures
can have a variety of shapes not limited to the posts 15 shown in Figure 2 herein,
and all such shape variations are included herein.
[0026] Resonant structures, here posts 15, are fabricated from resonating
material (e.g., from a conductor such as metal (e.g., silver, gold, aluminum and
platinum or from an alloy) or from any other material that resonates in the
presence of a charged particle beam). Other exemplary resonating materials
include carbon nanotubes and high temperature superconductors.
[0027] When creating the resonating elements 14, and the resonating structures
15, according to the present invention, the various resonant structures can be
constructed in multiple layers of resonating materials but are preferably
constructed in a single layer of resonating material as described hereinafter.
[0028] In one single layer embodiment, all the resonant structures 15 of a
resonant element 14 are formed by being etched, electroplated or otherwise
formed and shaped in the same processing step.
[0029] At least in the case of silver, etching does not need to remove the
material between segments or posts all the way down to the substrate level, nor
does the plating have to place the posts directly on the substrate. Silver posts can
be on a silver layer on top of the substrate. In fact, we discovered that, due to
various coupling effects, better results are obtained when the silver posts are set on
a silver layer, which itself is on the substrate.
[0030] As noted previously, the shape of the posts 15 may also be shapes other
than rectangles, such as simple shapes (e.g., circles, ovals, arcs and squares),
complex shapes (e.g., such as semi-circles, angled fingers, serpentine structures
and embedded structures (i.e., structures with a smaller geometry within a larger
geometry, thereby creating more complex resonances)) and those including
waveguides or complex cavities. The finger structures, regardless of any
particular shape, will be collectively referred to herein as "segments."
[0031] Turning now to specific exemplary embodiments, for example a chip 30
as shown in Figure 3, can be comprised of a substrate 32 that has been provided
with a thin layer of nickel 34, or other adhesive layer or material, at, for example,
a thickness of about 10 nm, and a layer of silver 36 having, for example, a
thickness of about 100 nm. As shown, the chip 30 includes two rows 38 and 40 of
posts or periodic structures, preferably adjacent one another, each being comprised
of a plurality of ultra-small structures or segments, which collectively comprise
an array of ultra small structures, a resonating element, which will resonate at two
different frequencies. For example, one row could be arranged to resonate at one
frequency while the other could be arranged to resonate at another and different
frequency. As explained above, and in the above copending applications, the
ultra-small structures in rows 38 and 40 can be formed by etching or plating
techniques, and can have a wide variety of shapes and sizes, with a variety of
spacing there between and a variety of heights. Through a selection of these
parameters as obtained by such processing techniques, and with reference to what
is desired to be accomplished, a chip 30 can be provided, for example, with a row
of a plurality of ultra-small structures that will produce, for example, green
light and another row, for example, that could produce and output, such as,
for example, red light. It must be understood and appreciated that the light
or other EMR being emitted by rows 38 and 40, when energized or excited
by a beam of charged particles as is shown at 41, is desirably achieved by
having the emission of energy be at any two different frequencies, whether
in the visible light spectrum, the microwave spectrum, the infra-red
spectrum or some other energy spectrum. The invention centers around
having ultra small structures formed in one layer of a conductive material,
and either isolated or connected as discussed herein, so that they will
resonate at two or more different frequencies.
[0032] The present invention is not limited to having only one array
comprised of two rows of ultra-small structures. For example, the invention
contemplates having a single row 42 comprised of a plurality of the ultra-
small resonant structure, but with the row 42 having two different sections, A
and B formed of different ultra-small resonant structures, with the A section
resonating at one frequency while the B section resonates at a different
frequency. In this instance, the two sections, A and B, will emit energy at
different frequencies even though they are contained in one row of
structures. Also, the present invention could, for example, also encompass a
device, such as a chip, where its surface is completely filled with or
occupied by various arrays of ultra-small structures each of which could be
identical to one another, where each was different, or where there were
patterns of similar and dissimilar arrays each of which could be emitting or
receiving energy or light at a variety of frequencies according to the pattern
designed into the arrays of ultra small structures. The processing techniques
discussed and disclosed herein, and in the above referenced applications
incorporated herein by reference, permit production of any order, design,
type, shape, arrangement, size and placement of arrays, elements, posts,
segments and/or ultra-small structures, or any grouping thereof, as a
designer may wish, in order to achieve an input, output onto or from the
surface of the chip to provide light, data transfer or other information or data
into or out of the chip or both, or between different parts of a chip or
adjacent chips.
[0033] Another exemplary array of resonant elements is shown in Figure 4,
where one wavelength element HOB, comprised of posts or fingers 115B, with a
spacing between posts or fingers shown at 120B 5 lengths at 125B and heights (not
shown), for producing electromagnetic radiation with a first frequency, for
example a blue color, has been constructed on a substrate 103 so as to be on one
side of a beam 130 of charged particles (e.g., electrons, or positively of negatively
charged ions)and a second wavelength element HOG, comprised of posts or
fingers 115G, with a spacing between posts or fingers shown at 120G, lengths at
125G and heights (not shown), for producing electromagnetic radiation with a
second frequency, for example a green color, has been constructed on a substrate
103 so as to be the opposite side of the beam 130. It should be understood that
other forms of these wavelength elements could be formed, including using a
wavelength element that would produce a red color could be used in place of
either the blue or green elements, or that combination elements comprised of ultra
small structures that would produce a variety of colors could also be used.
However, the spacing and lengths of the fingers 115G and 115B of the resonant
structures 11OG and HOB, respectively, are for illustrative purposes only and are
not intended to represent any actual relationship between the period or spacing 120
of the fingers, the lengths of the fingers 115 and the frequency of the emitted
electromagnetic radiation. However, the dimensions of exemplary resonant
structures are provided in Table 1 below including for red light producing
structures.
Table 1
[0034] As dimensions (e.g., height and/or length) change, the intensity of the
radiation may change as well. Moreover, depending on the dimensions, harmonics
(e.g., second and third harmonics) may occur. For post height, length, and width,
intensity appears oscillatory in that finding the optimal peak of each mode created
the highest output. When operating in the velocity dependent mode (where the
finger period depicts the dominant output radiation) the alignment of the
geometric modes of the fingers are used to increase the output intensity. However
it is seen that there are also radiation components due to geometric mode
excitation during this time, but they do not appear to dominate the output. Optimal
overall output comes when there is constructive modal alignment in as many axes
as possible.
[0035] We have also detected that, unlike the general theory on Smith-Purcell
radiation, which states that frequency is only dependant on period and electron
beam characteristics (such as beam intensity), the frequency of our detected beam
changes with the finger length. Thus, as shown in Figure 5, the frequency of the
electromagnetic wave produced by the system on a row of 220nm fingers (posts)
has a recorded intensity and wavelength greater than at the lesser shown finger
lengths. With Smith-Purcell, the frequency is related to the period of the grating
(recalling that Smith-Purcell is produced by a diffraction grating) and beam
intensity according to:
constant, β is related to the speed of the electron beam, and θ is the angle of
diffraction of the electron.
[0036] Each of the dimensions mentioned above can be any value in the
nanostructure range, i.e., 1 nm to 1 μm. Within such parameters, a series of posts
can be constructed that output substantial EMR in the infrared, visible and
ultraviolet portions of the spectrum and which can be optimized based on
alterations of the geometry, electron velocity and density, and metal/layer type. It
should also be possible to generate EMR of longer wavelengths as well. Unlike a
Smith-Purcell device, the resultant radiation from such a structure is intense
enough to be visible to the human eye with only 30 nanoamperes of current.
[0037] Fig. 6 shows another exemplary embodiment of the present
invention where two rows comprised of a plurality of resonating structures, 50 and
52, can be arranged in two parallel rows, or alternatively the rows can be arranged
at any desired angle. A charged particle beam 54 and 56 are directed past the rows
50 and 52, respectively by the operation of a magnetic element/cell 62 which can
be in one of two states, referred to here as 'TST" and "S". Such a magnetic
element/cell 62 is also referred to herein as a bi-state device or cell or element. A
beam 64 of charged particles (emitted by an emitter 66 - a source of charged
particles) is deflected by the magnetic element 62, depending upon and according
to the state of the magnetic element. When the magnetic element 62 is in its
so-called "N" state, the particle beam 64 will be deflected in the N direction, along
path 60 to a reflector 68 which then deflects the beam along a path 56 parallel to
row 52. When the magnetic element 62 is in its so-called "S" state, the particle
beam 64 will be deflected in the S direction along a path 58 toward a reflector 70
that then deflects the beam among a path 54 parallel to row 50. It should be
understood that rows 50 and 52 could be angled to be parallel with beam paths 58
and 60, respectively, or at any other angle with deflectors 70 and 68 being
appropriately angled to direct the beam along the row of resonating elements.
[0038] For the sake of this description, the drawings show the particle beam
traveling in both the N and the S directions. Those of skill in the art will
immediately understand that the charged particle beam will only travel in one of
those directions at any one time.
[0039] Fig. 7 shows another embodiment where a plurality of rows of
wavelength elements 200R-216B have been formed as a composite array on a
substrate 106 so that all three visible light spectrums can be produced by the array
(i.e., red, green and blue). The spacings between and the lengths of the fingers or
posts being used, 218R, 220G, and 222B of the resonant structures 200R-204R,
206G-210G, and 212B-216B, respectively, are for illustrative purposes only, and
are not intended to represent any actual relationship between the period or
spacings between the fingers or posts, the length of the fingers or posts and the
frequency of the emitted electromagnetic radiation. Reference can be made to
Table 1 above for specifics concerning these parameters.
[0040] As shown in Fig. 7, each row of resonant structures 200R-216B can
include its own source of charged particles 232, or as discussed above concerning
Fig. 6 a magnetic element or other forms of beam deflectors, as referenced in the
above related applications, which have been incorporated herein, can be used to
direct beams of charged particles past these rows of resonating structures. It
should also be understood that rows 200R, 202R and 204R, for example, could be
formed so that each produced exactly the same color and shade of red, or each
could be formed to produce a different shade of that color, for example light red,
medium red and/or dark red. This concept of having color shading applies equally
as well to the green and blue portions of the array.
[0041] Each row 200R-216B will produce a uniform light output, yet the
combination of the plurality of rows, and the plurality of fingers or posts in each
row, permits each row to be controlled so that the whole array can be tuned or
constructed, by a choice of the parameters mentioned herein and in the above
noted co-pending applications, to produce the light or other EMR output desired.
[0042] It should also be understood that the present invention is not limited to
having three rows of each of three colors, but rather to the concept of having at
least a sufficient number of ultra small structures that will produce two different
frequencies on the same surface at the same time. Thus, the chip or what ever
other substrate is to be used, could have, and the invention contemplates, all
possible combinations of ultra small structures whether in individual rows,
adjacent rows or non-adjacent rows, as well as all combinations of colors and
shadings thereof as are possible to produce, as well as all possible combinations of
the production of frequencies in other or mixed spectrums. Further, the surface
can have a limited number of ultra small structures that will accomplish that
objective including, as well, as many rows and as many ultra small structure as the
surface can hold, including individual rows each of which are comprised of a
plurality of different ultra small structures.
[0043] While the invention has been described in connection with what is
presently considered to be the most practical and preferred embodiment, it is
to be understood that the invention is not to be limited to the disclosed
embodiment, but on the contrary, is intended to cover various modifications
and equivalent arrangements included within the spirit and scope of the
appended claims.
Next Patent: MULTIPLEXED OPTICAL COMMUNICATION BETWEEN CHIPS ON A MULTI-CHIP MODULE