The present invention relates to a composition of matter based on lamellar materials, and method of deriving one or more predetermined number of layers of material from a bulk lamellar material.
Twenty-first century science and technology endeavors, research and development innovations that solve problems for man-kind will increasingly be dominated by the ability to make structures and objects that have sizes with length scales approaching those of atoms and molecules having dimensions of a nano-meter or less. Nano-scale matter and objects exhibit unique behaviors, some of which have yet to be revealed in addition to the known remarkable optical, thermal, electrical and mechanical properties. These open new vistas for many applications. For example, sequencing, imaging, nano-lithography, manipulation, nano-scale self assembly, nanometer scale chemistry, and many other applications with benefit from nano-scale technology development.
It is envisioned and believed that being involved in the nano-size frontier of science, technology and innovation is a sure path to regional and national economic well being, and competitiveness. This is evidenced by the extraordinary investment activities by big and small countries, large and small private sector enterprises and nearly unparalleled entrepreneurial activities.
To advance in the nano-scale frontier science and technology requires access to and mastering the following:
Key parameters become smaller by 10 to 20 orders of magnitude as compared to similar parameters in the macro-world. In the last 5 years the collective achievements of the best and brightest people around the world related to the above tools have grown at astonishing rates, delivering numerous discoveries, innovations, methods, products and tools.
Known techniques allow production of sub-micron objects and features that can be produced by means of conventional optical, UV, e-beam, X-ray and lithography. These tools are being extended to produce sizes below 30 nanometers. As they are stretched to produce even smaller sizes, their limitations become more and more apparent, in terms of cost, foot-print, etc. Indeed, at high electron and ion beam accelerating voltages >100KV features smaller that 10 nm have been demonstrated. The preparation steps and the cost of the equipment and ancillary components make these prior art methods cumbersome and slow.
Various embodiments presented in parent application Ser. No. 10/582,605 (and related PCT application Ser. No., 06/13681), incorporated by reference herein, depart from use of convention lithography based photon, ion and e-beams to produce the smallest features. Instead, ultra-thin films are used in parent application Ser. No. 10/582,605 for this purpose thereby allowing one to produce similar or better results with faster ramp-up times and with more convenience.
There are many known methods of producing films with atomic precision. These include, deposition by sputtering, electron beam, ion beam, molecular beam epitaxy, CVD, MOCVD, plasma, laser deposition, pyrolitic deposition, electrochemical, thermal evaporation, sputtering, electro-deposition, molecular beam epitaxy, adsorption from solution, Langmuir-Blodgett (LB) technique, self-assembly and many other related methods collectively referred to as Thin Film Deposition Methods. Accurate metrology enables the production and control of thicknesses with Angstrom precision. Producing free standing films by peeling is possible as taught in U.S. Pat. No. 7,045,878 and U.S. patent application Ser. No. 10/970,814 filed on Oct. 21, 2004 and manipulation and formation of vertically integrated devices of such films taught in applicant's U.S. Pat. No. 7,033,910, U.S. patent application Ser. No. 11/406,848, U.S. patent No. 6,875,671, U.S. patent application Ser. No. 11/020,753, U.S. patent application Ser. No. 10/719,663, U.S. patent No. 6,956,268, and U.S. patent application Ser. No. 10/793,653, all of which are incorporated by reference herein.
The advent of scanning tunneling microscopy (STM), atomic force microscopy, AFM, scanning probe microscopy, SPM, and related tools have enabled the imaging of surfaces and structures with atomic resolution. This has opened new avenues to advance our understanding of many physical and chemical phenomena that are being exploited in numerous practical applications in the fields of medicine, nanotechnology, nano-electronics, genomics, proteomics, nano-electrochemistry, and destined to make even more contributions in other fields in the futures.
To achieve nano-scale resolution and nanofabrication accuracy, and to properly interpret physical and chemical phenomena, it is desirable and oftentimes necessary to use atomically flat, atomically smooth substrates over a large area, for instance in the range of several square microns to several square centimeters. To produce such substrates, conventional methods rely on unsophisticated and inaccurate techniques of attaching an adhesive tape to the surface of mica or graphite to peel the top most atomic layers to reveal a fresh atomically smooth surface of a piece of mica or graphite of size and thickness. In almost all situations the atomic surface is the desired result while the lateral shape or size or thickness is of little importance. Conventional techniques could not teach methods of producing, handling and manipulating samples having a single layer of graphite (also called graphene) or mica, for example, or a predetermined desired number of mono-atomic of mica or graphite layers.
Graphites are well known and are widely used materials. For example U.S. Pat. No. 6,538,892 exploits its good mechanical and anisotropic thermal properties for the construction of heat sinks. Graphites according to the description in U.S. Pat. No. 6,538,892, are made up of layer planes of hexagonal arrays or networks of carbon atoms. These layer planes of hexagonally arranged carbon atoms are substantially flat and are oriented or ordered so as to be substantially parallel and equidistant to one another, as shown in
Briefly, graphites may be characterized as laminated structures of carbon, that is, structures consisting of superposed layers of carbon atoms joined together by weak van der Waals forces 112. In considering the graphite structure, two axes or directions are usually noted, to wit, the “c” axis or direction and the “a” axes or directions. For simplicity, the “c” axis or direction may be considered as the direction perpendicular to the carbon layers. The “a” axis or directions may be considered as the directions parallel to the carbon layers or the directions perpendicular to the “c” direction. The graphites suitable for manufacturing flexible graphite sheets possess a very high degree of orientation.
The bonding forces holding the parallel layers of carbon atoms together are only weak van der Waals forces. In a process referred to as exfoliation of graphite, natural graphites can be treated so that the spacing 112, d, in
Recently, Andrei Geim and colleagues of the University of Manchester isolated a single sheet of graphene and measured its remarkable properties which include conductivity 100 higher than copper and astonishing Quantum Hall Effect behavior. These and other results are described in January, 2006 , Physics Today. These results could be made possible only after successful isolation of a single 1 Angstrom graphene layer, a feat that was not previously possible. Geim's team succeeded in isolating a single graphene layer by random, tedious and unpredictable method.
According to the Physics Today Article:
The work confirmed that graphene is remarkable—stable, chemically inert, and crystalline under ambient conditions.”
In another approach, a team led by Walt A. de Heer of the Georgia Institute of Technology in Atlanta produced graphene by heating the surface of a wafer of silicon carbide so that the silicon atoms evaporated, leaving behind a few layers of carbon atoms that assembled into graphene. As taught therein, a thin-film graphitic layer is produced by annealing preselected crystal face of a crystal.
In still another approach, Stankovich et al. derived exfoliated graphene oxide and attempted to reduce the graphene oxide to graphene, as an additive to enhance conductivity of graphene-polymer composites. Graphite oxides were chemically modified by treating graphite oxide with organic isocyanates to reduce the hydrophilic character of graphene oxide sheets. These isocyanate-derivatized graphite oxides form stable dispersions in polar aprotic solvents (such as N,N-dimethylformamide (DMF)), consisting of completely exfoliated, functionalized individual graphene oxide sheets with thickness 1 nm. These dispersions of isocyanate-derivatized graphite oxide allow graphene oxide sheets to be intimately mixed with many organic polymers to form graphene-polymer composites.
From the above and other recent investigations on graphene as well as from commercial supplier of graphite substrate, one concludes that there remains a need for inventing convenient, low cost, and fast methods for isolating single layers of graphene and predictable stacks of selected number of graphene layers. There further remains a need for methods for isolating single layer or predictable number of layers from lamellar or multilayer materials in general.
In addition to methods for isolating single layer or predictable number of layers from lamellar or multilayer materials in general, there remains a need to accurately form layers of graphene or other carbon based materials into virtually any desired shape to fit the application, for example, as a nanotool or component of a nanotool.
Conventional approaches to shaping and cutting on a nanoscale level, particularly cutting ultra thin (e.g., single atomic layer) are limited. Conventional cutting techniques, for example, those based on laser cutting, water jet, mechanical cutting tools, plasma cutting, or chemical etching exist, but have limitations as to the ability to control the cut depth in a convenient manner.
U.S. Pat. No. 6,869,581 teaches “cutting” by globurization of a deposited metal after pretreatment including heating the deposited metal close to its melting point in an oxygen atmosphere to induce oxidation.
With the advent of nanoscale materials and tools, a need exists for a suitable method to cut or define features of atomic layers of material, such as layers of graphene. However, using conventional approaches, it is not possible to cut to a selected depth (e.g., cut only one layer or to a selected depth of a multilayer structure). Furthermore, to minimize or avoid the need for post-cutting processing operations, for example, to remove defects and the like, cutting operations should not be detrimental to the material characteristics. Therefore, a need remains for efficient and accurate methods and systems for cutting or defining features within atomic layers of material.
Embodiments of the present invention described herein teach new methods, devices and tools that advances the nanotechnology art listed above. By departing from methods of prior art and adding new techniques departing form the teaching of the prior art, embodiments of the present invention provide the ability to make free standing nano-thickness atomically smooth films, including single or multiple layers from layered or lamellar materials including but not limited to such as mica, WS2, super lattices, MoS2, YBCO (yttrium barium copper oxide) and other related superconductors, NbSe2, Bi2Sr2CaCu2Ox, graphite, boron nitride, dichalcogenide, trichalcogenide, tetrachalcogenide, pentachalcogenide, double hydroxides, anionic clays and hydrotalcite-like materials. These single or multiple layers can be used as substrates and or components for nanotools, and as starting materials for use to create unique composite materials of many different types of compositions and configurations.
Accordingly, certain objects herein are to produce single or predetermined numbers of known mono-atomic layers of graphene, mica and other layered or lamellar materials such as WS2, super lattices, MoS2, YBCO (yttrium barium copper oxide) and other related superconductors, NbSe2, Bi2Sr2CaCu2Ox, graphite, boron nitride, dichalcogenide, trichalcogenide, tetrachalcogenide, pentachalcogenide, double hydroxides, anionic clays and hydrotalcite-like materials, conveniently and inexpensively. Another object of this aspect of the invention to separate or exfoliate single mono-atomic layers from layered or lamellar materials including but not limited to layers of graphene and other lamellar or layered material derivative, and attaching them to substrate through a releasable bond.
In one aspect of the present invention, a material comprising a predetermined number of one or more layers is provided. The one or more layers are layers of a lamellar material that are weakly bonded to each other. In contrast to conventional processing of lamellar materials such as graphite, where random numbers of graphene layers are attempted to be derived from graphite, in the material according to aspects of the present invention, predetermined numbers of layers are provided.
In another aspect of the present invention, the predetermined number of layers are at least partially supported by a substrate.
In another aspect of the present invention, the predetermined number of layers are permanently attached to at least a portion of a substrate.
In another aspect of the present invention, the predetermined number of layers are removably attached to least a portion of a substrate.
In another aspect of the present invention, the at least one layer is an atomic layer of carbon atoms.
In another aspect of the present invention, the layer is a layer of graphene.
In another aspect of the present invention, at least a portion of a surface of said material is atomically flat.
In another aspect of the present invention, the at least one predetermined number of layers comprises a plurality a layers, wherein said plurality of layers is exfoliated.
In another aspect of the present invention, a composite material is provided including the material comprising a plural predetermined number of one or more layers and at least one introduced atomic or molecular species. In certain embodiments, the introduced atomic or molecular species is present at predefined depths between one or more of said plural layers. In certain other embodiments, the introduced atomic or molecular species is present at random depths between one or more of said plural layers. In certain further embodiments, the introduced atomic or molecular species is present at predefined areas of said material.
In another aspect of the present invention, a composite material is provided including the material comprising a predetermined number of one or more layers at least one layer of another material.
In another aspect of the present invention, a composite material is provided including a predetermined number layers of a first material layered with a predetermined number layers of a second material. In certain embodiments, the composite material further includes at least one introduced atomic or molecular species. In certain other embodiments, the introduced atomic or molecular species is present at random depths between one or more of said plural layers. In certain further embodiments, the introduced atomic or molecular species is present at predefined areas of said material.
In further aspects of the present invention, methods are provided for forming a predetermined number of layers of a lamellar material.
In one aspect of the present invention, a method of deriving a predetermined number of layers of a lamellar material includes permanently or removably attaching a substrate to a surface of a lamellar material having a plurality of layers that are weakly bonded to each other and applying a mechanical force at an edge between adjacent or non-adjacent layers with a tool having a knife edge configuration and a suitable tip edge thickness (e.g., sharpness).
In another aspect of the present invention, a method of deriving a predetermined number of layers of a lamellar material includes permanently or removably attaching a substrate to a surface of a lamellar material having a plurality of layers that are weakly bonded to each other, and applying a mechanical force between terminal ends with a tool having a knife edge configuration and a suitable tip edge thickness (e.g., sharpness). In further embodiments of this method, a mechanical force is also applied between terminal ends at another location of the layers with a tool having a knife edge configuration a suitable tip edge thickness (e.g., sharpness).
In another aspect of the present invention, a method of deriving a predetermined number of layers of a lamellar material includes permanently or removably attaching a substrate to a surface of a lamellar material having a plurality of layers that are weakly bonded to each other. The lamellar material is provided with a first layer having a first terminal end with an exposed face facing in a first direction and a second layer having a first terminal end in step configuration with the first terminal end of the first layer. Additionally, the first layer further including a second terminal end and the second layer further including a second terminal end with an exposed face, the first terminal ends being in a step configuration. A mechanical force is applied toward the exposed face of the second layer in a direction generally opposite the substrate thereby lifting off the predetermined number of layers. In certain other embodiments of this method, a mechanical force is also applied toward the exposed face of said first layer in a direction generally toward the substrate., so as to provide a “twits” lift-off action.
In another aspect of the present invention, a method of deriving a predetermined number of layers of a lamellar material includes applying a current between an electrode on or within a substrate attached to a lamellar material and a selected layer of the lamellar material, so as to create separation force whereby the interlayer forces between the selected layer and an adjacent layer proximate are decreased. In a further embodiment of this method, interlayer forces between the selected layer and the adjacent layer are decreased sufficiently to cause physical separation. In still further embodiments of this method, a mechanical force is also applied to pull one or more predetermined number of layers.
In another aspect of the present invention, a method of deriving a predetermined number of layers of a lamellar material includes applying a voltage between one or more electrode on or within a substrate attached to the lamellar materials and a selected layer; so as to create a separation force whereby the interlayer forces between the selected layer and an adjacent are decreased. In a further embodiment of this method, interlayer forces between the selected layer and the adjacent layer are decreased sufficiently to cause physical separation. In still further embodiments of this method, a mechanical force is also applied to pull one or more predetermined number of layers.
In another aspect of the present invention, a method of deriving a predetermined number of layers of a lamellar material includes permanently or removably attaching a first substrate to a first surface of a lamellar material having a plurality of layers that are weakly bonded to each other, the first substrate attached with an attachment force greater than the interlayer forces of the lamellar material. A second substrate is also permanently or removably attaching a second substrate to a second surface of the lamellar material. The first substrate is lifted to separate one or more layers of the lamellar material from other layer or layers of the lamellar material attached to the second substrate. This process may be repeated until a predetermined number of atomic layers is derived.
The foregoing summary as well as the following detailed description of preferred embodiments of the invention will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the various embodiments and aspects of the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown in the drawings, where:
Certain aspects of the present invention provides convenient, low cost, and fast methods for isolating single layers of graphene and predictable stacks of selected number of graphene layers. Methods for isolating single layer or predictable number of layers from lamellar or multilayer materials are also provided by certain aspects of the present invention. Lamellar or multilayer materials that may be used to isolate a single layer or a predictable number of layers include but are not limited to mica, WS2, super lattices, MoS2, YBCO (yttrium barium copper oxide) and other related superconductors, NbSe2, Bi2Sr2CaCu2Ox, graphite, boron nitride, dichalcogenide, trichalcogenide, tetrachalcogenide, pentachalcogenide, double hydroxides, anionic clays and hydrotalcite-like materials.
Therefore, many aspects of the present invention involve production of single and a predetermined number of multiple layers of lamellar material. Many of the inventive features and certain embodiments of the present invention rely on the ability to make ultra-thin, nano-scale films. In further embodiments, it is desirable that these films are atomically flat films. These enable the fabrication of all the probe configurations that perform a variety of functions necessary to advance the frontier of nano-science and technology including but not limited to imaging, analysis, sequencing, nano-lithography, and nano-manipulation as well a variety of other applications. Thin film deposition methods describe above may be used to produce thing films with Angstrom precision. Alternatively, even more precisely define thickness can be produced the controlled peeling of one or more predetermined number of layers from lamellar material as taught herein. These embodiments described herein apply to lamellar or multilayer materials, including but not limited to graphite to produce graphene layers, layers of mica, MoS2 and other lamellar or multilayer materials.
One embodiment to selectively peel off a single layer from a lamellar material, 210, is illustrated in
In another embodiment, knife edges 218, 220, are applied in the horizontal directions pushing on both sides pry loose the first layer while the substrate 216 is pulling upward. The substrate 216 may be permanently bonded or removably bonded to the first layer 222. Removable bonding may be accomplished by various bonding and handling techniques including but not limited to adhesives, waxes, and vacuum handlers.
This methods illustrated in
After the etching is complete, the exposed second layer 312 is pushed as in
The substrate 316 is removably bonded to the first layer 322 by many bonding and handling techniques including but not limited to adhesives, waxes, and vacuum handlers. The final result in 3C may be repeated for all the other layers of the lamellar material until all layers are removed with minimum of waste. This method can also be combined with method described in
Another embodiment that takes advantage of the unique properties of graphene and other metallically coated lamellar materials is described in
Instead of exploiting the magnetic force in the aforementioned embodiment, it is possible to use instead electrostatic force as illustrated in FIGS. 5A-B. In this case a voltage source 516 is applied to electrode 524, deposited on substrate 512 and a revealed portion of the first layer 522. The electric field 520 is applied and causes an electrostatic force in the upward direction 518, and along with a mechanical force applied to a substrate upward in a pulling selection, the first layer is selectively removed from the entire multi layer structure 510. Furthermore, in combination with various other techniques described herein, the method and system of
681 Another embodiment of peeling layers of lamellar material is shown in FIGS. 6A-C. Here the multilayer lamellar structure 610 is attached to a substrate 614 to the bottom while at the top implement substrate 612 is removably attached to the top of the specimen. Said substrate 612 may be a vacuum handler, adhesive tapes or other films with removable adhesives. The first step is to lift substrate 612 which will pull or peel a random number of layers 616, shown in
The above embodiments of methods to selectively remove single layers, or predetermined number of layers from lamellar could be combined as appropriate to achieve most advantageous, practical and economical way to produce the desired results.
Referring now to
Referring now to
Referring to
In certain preferred embodiments, a narrow energy distribution is selected to achieve a narrow depth penetration or intercalation distribution species. This allows selection of a consistent depth, or number of layers penetrated.
Note that smaller energy doses may be required for embodiments of the present invention whereby graphene one of plural layers as compared to traditional semi-conductor material implantation methods. Since the van Der Walls forces between layers are very weak, smaller dosages (in terms of current and or voltage) is required.
In certain other embodiments of the present invention, a broad energy distribution, e.g., ranging from about 50 V to about 10 kV, is selected to selected to allow penetration intercalation of species over a number of layers. For example, such a composite, having penetrated catalytic species therethrough, may serve as an oxidation catalyst (including, for example, H+, Cs+, Li+, Na+, K+) for various cutting embodiments as described in co-pending application number 11/______, filed on the same date hereof, under Express Mail Label Number EV443782141US (Attorney Docket Number REVEO-0260USAAPN39), entitled “Method Of and System For Cutting Carbon Based Materials”, which is incorporated by reference herein. This penetration or intercalation further may take place starting from designated areas of an exposed surface of the lamellar material, thereby allowing for specific areas of a planar surface to be implanted, as shown in
Referring now to
While preferred embodiments have been shown and described, various modifications and substitutions may be made thereto without departing from the spirit and scope of the invention. Accordingly, it is to be understood that embodiments of the present invention has been described by way of illustrations and not limitation.
This application is a Continuation in Part of U.S. Non-provisional application Ser. No. 10/582,605 filed on Jun. 9, 2006, which is a national phase filing under 35 USC 371 of PCT application Ser. No., 06/13681 filed on Apr. 7, 2006, entitled “Probes, Methods of Making Probes and Applications of Probes”, which claims priority to U.S. Provisional Application Nos. 60/669,029 filed on Apr. 7, 2005 entitled “DNA Sequencing Method and System” and 60/699,619 filed on Jul. 15, 2005 entitled “Molecular Analysis Probe, Systems and Methods, including DNA Sequencing”, and is related to U.S. Non-provisional 11/______ ,filed on the same date as the present application, under Express Mail Label Number EV443782141US (Attorney Docket Number REVEO-0260USAAPN39), entitled “Method Of and System For Cutting Carbon Based Materials”, and U.S. Non-provisional 11/______, filed on the same date as the present application, under Express Mail Label Number EV443782138US (Attorney Docket Number REVEO-0260USAAPN40), entitled “Method of and System For Forming Nanostructures and Nanotubes” all of which are incorporated by reference herein.
Number | Date | Country | |
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60669029 | Apr 2005 | US | |
60699619 | Jul 2005 | US |
Number | Date | Country | |
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Parent | 10582605 | US | |
Child | 11496059 | Jul 2006 | US |