Patent Publication Number: US-2022236264-A1

Title: Field effect transistor, device including the transistor, and methods of forming and using same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority to U.S. patent application Ser. No. 16/697,769 filed Nov. 27, 2019, entitled FIELD EFFECT TRANSISTOR, DEVICE INCLUDING THE TRANSISTOR, AND METHODS OF FORMING AND USING SAME; which is a continuation of U.S. patent application Ser. No. 15/156,213, filed on May 16, 2016 (now U.S. Pat. No. 10,514,380), entitled FIELD EFFECT TRANSISTOR, DEVICE INCLUDING THE TRANSISTOR, AND METHODS OF FORMING AND USING SAME, which is a continuation of U.S. patent application Ser. No. 14/391,661, filed on Oct. 9, 2014 (now U.S. Pat. No. 9,341,592), entitled FIELD EFFECT TRANSISTOR, DEVICE INCLUDING THE TRANSISTOR, AND METHODS OF FORMING AND USING SAME, which is the U.S. National Phase entry of International Application No. PCT/US2013/035852, filed on Apr. 9, 2013, entitled FIELD EFFECT TRANSISTOR, DEVICE INCLUDING THE TRANSISTOR, AND METHODS OF FORMING AND USING SAME, which claims the benefit to U.S. Provisional Patent Application Ser. No. 61/621,966, filed on Apr. 9, 2012, entitled FIELD EFFECT NANOPORE DEVICE AND CHEMICAL-STOP NANOPORE ETCHING FOR GENOME SEQUENCING, PROTEIN SEQUENCING AND OTHER APPLICATIONS, and U.S. Provisional Patent Application Ser. No. 61/802,235, filed on Mar. 15, 2013, entitled FIELD EFFECT NANOPORE TRANSISTOR DEVICE METHODS OF FORMING AND USING THE SAME, the disclosures of which are incorporated herein by reference to the extent such disclosures do not conflict with the present disclosure. 
    
    
     GOVERNMENT LICENSE RIGHTS 
     This invention was made with government support under grant number 5R21HG006314 awarded by NIH. The United States government has certain rights in the invention. 
    
    
     FIELD OF THE INVENTION 
     The present invention generally relates to field effect transistors and devices including the transistors. More particularly, the invention relates to field-effect transistors suitable for detection of various materials, to devices including the transistors and to methods of forming and using the transistors and devices. 
     BACKGROUND OF THE INVENTION 
     Various sensors can be used to detect and characterize materials, such as biological, chemical, and/or radiological materials. For example, nanopore or nanochannel sensors have been developed to detects and characterize biological materials. In recent years, nanopore based sequencing approaches for detecting and characterizing biological materials have gained interest because such techniques offer two distinct advantages over other technology platforms, including: (i) point transduction capability and (ii) high speed nanopore translocation. Methods of nanopore based sequencing of biological material include: ion current blockade technique and more recently, transverse electron transport techniques. While these techniques hold promise to deliver a solution that is able to read-out the three billion base pairs at low cost and in a reasonably short period of time, they suffer from few fundamental limitations. 
     Ion current blockade techniques are limited by relatively low ion mobility in aqueous solution, when measuring ion-current across a nanopore. A recent study shows a current response over a time period of 10 4  micro seconds for a step input applied and measured across a nanopore device, potentially limiting the rate of sequencing to below 1000 bases per second. Transverse electron transport measurements on the other hand are limited in sequencing-speed by quantum mechanical noise. In both ion current blockade and transverse electron transport techniques, these limitations result in failure to exploit the most significant advantage of high-speed DNA translocation in nanopore. Researchers have thus used methods to slow-down the DNA, from its natural high speed translocation of few million bases per second in solid state nanopores and up to 100 million bases per second in graphene nanopores. 
     A low cost, high quality solution to whole genome sequencing is generally desirable. Such a technology at low cost could lead to true personalized diagnostics and personalized therapeutics. Various technologies aim to provide just such a solution utilizing various technology approaches. However, such systems are generally expensive and therefore out of reach for many patients. Accordingly, a device and method where the total cost, cumulative of devices, instrumentation, reagents, time-cost and other resources, is relatively low, i.e., a desktop sequencer that will enable monitoring of mutations in a tumor over a period of time, and avails genome sequencing even to poorer countries, are desired. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved field effect transistor and device that can be used to sense and characterize a variety of materials. The field effect transistor and/or device including the transistor may be used for a variety of applications, including genome sequencing, protein sequencing, biomolecular sequencing, and detection of ions, molecules, chemicals, biomolecules, metal atoms, polymers, nanoparticles and the like. For example, the device can be used for detecting un-modified proteins, DNA and other biomolecules or proteins, DNA, biomolecules that have been modified with chemical tags or metal atom tags, nanoparticle tags, hybridization markers, or the like. 
     As set forth in more detail below, exemplary devices in accordance with various embodiments of the invention, take advantage of one or more of field effect transistor transduction mechanism and electric field focusing (e.g., at a bi-feature, e.g., conical or pyramidal sub-1000 nm to sub-10 nm nanopore). The field effect transistors and devices described herein can be operated in accumulation, depletion, partial depletion, full depletion, inversion or volume inversion mode. 
     In accordance with various embodiments of the disclosure, a device includes a substrate, an etch region formed within a portion of the substrate, an insulating region formed proximate the etch region, a source region overlying the insulating region and a first surface of the substrate, and a drain region formed overlying the insulating region and a second surface of the substrate. In accordance with various exemplary aspects of these embodiments, the device is capable of sensing and differentiating biological, chemical, and/or radiological species. The substrate may include conducting material, such as metal, semiconducting material, and/or insulating material. The device may include an additional semiconducting, metallic, or insulating layer proximate the insulating region. In accordance with further aspects, the substrate is selected from the group consisting of silicon, silicon on insulator, silicon on sapphire, silicon on silicon carbide, silicon on diamond, gallium nitride (GaN), GaN on insulator, gallium arsenide (GaAs), GaAs on insulator, germanium or germanium on insulator. In accordance with further aspects, the etch region includes a shape selected from the group comprising conical, pyramidal, spherical, or that has a cross section in the shape of a circle, rectangle, polygon, or slit. In accordance with yet further aspects of the disclosure, the device further includes a dielectric layer overlying a portion of the source region and/or the drain region. In accordance with yet further aspects, the device includes thin-film coating of material (e.g., organic, inorganic, or biological material) to facilitate detection of one or more chemical, biological, and/or radioactive materials. The thin-film coating may cover a portion of the device surface, such as the surface within the etch region. The device may include a nanopore, having a diameter of from about 1 nm to about 1000 nm, through the etch region. 
     In accordance with additional embodiments of the disclosure, a device includes an insulating substrate, an etch region formed within a portion of the insulating substrate, a layer formed of one or more of semiconducting, conducting, or topological insulating material formed overlying the insulating layer, a source region formed overlying the layer and a first surface of the substrate and a drain region formed overlying the layer and a second surface of the substrate. Various layers of devices in accordance with these embodiments may be formed of the same materials described above for the corresponding device layers. In accordance with yet further aspects, the device includes thin-film coating of material (e.g., organic, inorganic, or biological material) to facilitate detection of one or more chemical, biological, and/or radioactive materials. The thin-film coating may cover a portion of the device surface, such as the surface within the etch region. The device may include a nanopore, having a diameter of from about 1 nm to about 1000 nm, through the etch region. 
     In accordance with additional embodiments of the disclosure, a method of forming a device includes the steps of providing a substrate (e.g., a semiconductor, conductor, or insulator), etching a portion of the substrate to form an etch region, forming an insulating region proximate the etch region, forming a source region overlying the insulating region and a first surface of the substrate, and forming a drain region overlying the insulating region and a second surface of the substrate. In accordance with exemplary aspects of these embodiments, the step of providing a substrate includes providing a substrate comprising semiconductor material, such as silicon, silicon on insulator, silicon on sapphire, silicon on silicon carbide, silicon on diamond, gallium nitride (GaN), GaN on insulator, gallium arsenide (GaAs), GaAs on insulator, germanium or germanium on insulator. In accordance with further aspects, the step of forming an insulating region comprises one or more techniques selected from the group consisting of implantation (e.g., oxygen implantation), thermal oxidation, chemical vapor deposition, spin coating, vapor coating, spray coating, and dip coating. In accordance with further aspects, the step of etching includes etching along a crystalline plane of the substrate. Such etching may be self-limiting. The method may further include a step of annealing to obtain desired layer and/or device properties. In accordance with yet additional aspects of these embodiments, the method further includes the step(s) of forming a mask on the first surface and/or on the second surface within the etch region, which may be done using self-aligned technology. The method may further include the step of forming a nanopore (e.g., having a diameter between about 1 nm and 1000 nm) through the substrate. In accordance with various aspects of these embodiments, the nanopore is formed using one or more of: ion milling, electron beam milling, laser techniques; chemical stop wet etching, and wet etching. In accordance with yet additional aspects of these embodiments, the method may further include a step of depositing a semiconductor layer, metal layer, and/or a second insulating overlying the insulating layer. The method may further include forming at least one biological nanopore and/or chemical nanopore, which may be proximate a solid-state nanopore. 
     In accordance with additional embodiments of the disclosure, a method of forming a device includes the steps of providing a substrate (e.g., a semiconductor, conductor, or insulator), etching a portion of the substrate to form an etch region, and forming a layer selected from the group consisting of semiconducting layer, a metal layer, and a second insulating layer proximate the etch region. In accordance with various aspects of these embodiments, the method further comprises forming a source region overlying a first surface of the substrate and/or forming a drain region overlying a second surface of the substrate. In accordance with further aspects, the etching occurs along a crystalline plane of the substrate. The etching process may be self-limiting. In accordance with further aspects, the method includes an annealing step. The method may also include the step of forming a layer selected from the group consisting of semiconducting layer, a metal layer, and a second insulating layer proximate the etch region. The method may also include a step of forming a mask, which may be a self-aligned process. In accordance with further aspects, the method includes forming at least one nanopore though the substrate. The nanopore may be formed, for example, using one or more of ion milling, electron beam milling, laser, chemical stop wet etching, and wet etching. In accordance with further aspects, the method includes forming at least one lipid bilayer overlaying a nanopore. The method may further include forming at least one biological nanopore and/or chemical nanopore, which may be proximate a solid-state nanopore. 
     In accordance with yet further exemplary embodiments of the disclosure, a method of sensing material, such as chemical, biological, or radiological material (e.g., an ion, atom, or molecule) includes the steps of providing a device as described herein, providing material to be sensed, passing the material through a nanopore of the device; and detecting a variation in an electrical property of the device as the material passes through the nanopore. The material may be organic material, a nanoparticle, ionic species, molecular species, such as material selected from the group consisting of a DNA molecule, a protein molecule, a peptide molecule, a polypeptide molecule, an RNA molecule, a synthetic oligo nucleotide molecule, and a synthetic peptide or polypeptide molecule. The material to be sensed may be modified with at least one tag selected from the group consisting of metal species, metal-organic species, chemical modifiers, biomolecular tags, complementary hybridizing chain molecules, peptides, polypeptides, oligonucleotides, zinc fingers, nano particles, quantum dots, organic dyes, beads, nanowires, nanotubes. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
       The exemplary embodiments of the present invention will be described in connection with the appended drawing figures. 
         FIG. 1  illustrates a field effect transistor device in accordance with exemplary embodiments of the disclosure. 
         FIG. 2  illustrates another exemplary field effect transistor device in accordance with exemplary embodiments of the disclosure. 
         FIG. 3  illustrates steps of forming a field effect transistor device in accordance with exemplary embodiments of the disclosure. 
         FIG. 4  illustrates steps of forming a field effect transistor device in accordance with exemplary embodiments of the disclosure. 
         FIG. 5  illustrates steps of forming a field effect transistor device in accordance with exemplary embodiments of the disclosure. 
         FIG. 6  illustrates a nanopore formed in accordance with various exemplary embodiments of the disclosure. 
         FIG. 7  illustrates a simulation of one nano-ampere inversion current response to 0.01 V variation in floating gate (nanopore) potential. 
         FIG. 8  illustrates a method of detecting material in accordance with additional exemplary embodiments of the disclosure. 
         FIG. 9  illustrates another exemplary field effect transistor device in accordance with exemplary embodiments of the disclosure. 
         FIG. 10  illustrates another exemplary nanopore in accordance with exemplary embodiments of the disclosure. 
     
    
    
     It will be appreciated that the figures are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of illustrated embodiments of the present invention. 
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION 
     The description of exemplary embodiments of the present disclosure provided below is merely exemplary and is intended for purposes of illustration only; the following description is not intended to limit the scope of the invention disclosed herein. Moreover, recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features or other embodiments incorporating different combinations of the stated features. 
     Device Structure: 
       FIG. 1  illustrates a device  100  in accordance with various exemplary embodiments of the disclosure. Device  100  includes a substrate  102 , an etch region  118  formed within a portion of substrate  102 , an insulating region  104  formed proximate etch region  118 , a source region  112  overlying insulating region  104  and a first surface  120  of substrate  102 , and a drain region  110  formed overlying insulating region  104  and a second surface  122  of substrate  102 . As illustrated, source region  112  and drain region  110  may be formed using layer  106 . Device  100  may additionally include a dielectric layer  108 . A width of the device  100  can be from 1 angstrom to about 10 millimeter or more. 
     As used herein, overlying is not restricted to meaning that a layer overlying another layer must be immediately adjacent the other layer. Various layers may be interposed between a substrate or layer and another layer overlying the substrate or layer. For example, in the illustrated device, layer  104  overlies substrate  102 , layer  106  overlies layer  104  and substrate  102 , and layer  108  overlies layer  106 , layer  104 , and substrate  102 . Further, as used herein, a first surface and a second surface are not on a same side (e.g., top or bottom) of a structure or device, and in the illustrated examples are on opposite sides—top and bottom—of a substrate/device. 
     Substrate  102  may be formed of a variety of materials. For example, substrate  102  may include buried semiconductor material or a metal layer. Examples of substrate  102  material include, but are not limited to, semiconductors and metals, including silicon, germanium, graphene, diamond, tin or compound semiconductors like silicon carbide, silicon germanium, diamond, graphite, binary materials like aluminium antimonide (AlSb), aluminium arsenide (AlAs), aluminium nitride (AlN), aluminium phosphide (AlP), boron nitride (BN), boron phosphide (BP), boron arsenide (BAs), gallium antimonide (GaSb), gallium arsenide (GaAs), gallium nitride (GaN), gallium phosphide (GaP), indium antimonide (InSb), indium arsenide (InAs), indium nitride (InN), indium phosphide (InP), cadmium selenide (CdSe), cadmium sulfide (CdS), cadmium telluride (CdTe), zinc oxide (ZnO), zinc selenide (ZnSe), zinc sulfide (ZnS), zinc telluride (ZnTe), cuprous chloride (CuCl), lead selenide (Pb Se), lead sulfide (PbS), lead telluride (PbTe), tin sulfide (SnS), tin telluride (SnTe), bismuth telluride (Bi2Te3), cadmium phosphide (Cd3P2), cadmium arsenide (Cd3As2), cadmium antimonide (Cd3Sb2), zinc phosphide (Zn3P2), zinc arsenide (Zn3As2), zinc antimonide (Zn3Sb2), other binary materials like lead(II) iodide (PbI2), molybdenum disulfide (MoS2), gallium Selenide (GaSe), tin sulfide (SnS), bismuth Sulfide (Bi2S3), platinum silicide (PtSi), bismuth(III) iodide (BiI3), mercury(II) iodide (HgI2), thallium(I) bromide (T1Br), semiconducting oxides like zinc oxide, titanium dioxide (TiO2), copper(I) oxide (Cu2O), copper(II) oxide (CuO), uranium dioxide (UO2), uranium trioxide (UO3), 6.1 Å materials, or ternary materials like aluminium gallium arsenide (AlGaAs, AlxGa1-xAs), indium gallium arsenide (InGaAs, InxGa1-xAs), aluminium indium arsenide (AlInAs), aluminium indium antimonide (AlInSb), gallium arsenide nitride (GaAsN), gallium arsenide phosphide (GaAsP), aluminium gallium nitride (AlGaN), aluminium gallium phosphide (AlGaP), indium gallium nitride (InGaN), indium arsenide antimonide (InAsSb), indium gallium antimonide (InGaSb), cadmium zinc telluride (CdZnTe, CZT), mercury cadmium telluride (HgCdTe), mercury zinc telluride (HgZnTe), mercury zinc selenide (HgZnSe), lead tin telluride (PbSnTe), thallium tin telluride (T12SnTe5), thallium germanium telluride (T12GeTe5) and quaternary like aluminium gallium indium phosphide (AlGaInP, InAlGaP, InGaAlP, AlInGaP), aluminium gallium arsenide phosphide (AlGaAsP), indium gallium arsenide phosphide (InGaAsP), aluminium indium arsenide phosphide (AlInAsP), aluminium gallium arsenide nitride (AlGaAsN), indium gallium arsenide nitride (InGaAsN), indium aluminium arsenide nitride (InAlAsN), copper indium gallium selenide (CIGS), or quinary materials like gallium indium nitride arsenide antimonide (GaInNAsSb), Mg, Al, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, La, Hf, Ta, W, Re, Os, Ir, Pt, Au, TaTi, Ru, HfN, TiN, and the like. Substrate  102  may include inorganic or organic semiconducting material as described in more detail below in connection with layer  106 . In accordance with exemplary embodiments of the disclosure, substrate  102  is used as a gate to modulate conductivity of channel in layer  106 . In accordance with these embodiments, substrate  102  may include, for example, an elemental or compound semiconductor, a metal, a metal alloy, a metal-semiconductor alloy, a semi metal, or any other organic or inorganic material suitable for use as a metal-oxide-semiconductor field-effect transistor (MOSFET) gate. This layer can be of any suitable thickness. In flexible devices this layer includes a flexible substrate, such as, for example an organic material like pentacene. 
     Insulating region  104  may be formed of any suitable insulating material. In accordance with exemplary aspects of various exemplary embodiments of the disclosure, region  104  is a gate insulator or gate dielectric layer suitable for establishing inversion, depletion or accumulation in a channel region of layer  106 . 
     Inversion, depletion, or accumulation in layer  106  can be established using substrate bias or solution bias or portions of layer  106  can be inverted, depleted, or accumulated, without application of an external bias. Insulating region  104  can be made of any suitable organic or inorganic insulating material. Examples include, but are not limited to, silicon dioxide, silicon nitride, hafnium oxide, alumina, magnesium oxide, zirconium oxide, zirconium silicate, calcium oxide, tantalum oxide, lanthanum oxide, titanium oxide, yttrium oxide, titanium nitride, and the like. By way of one example, region  104  is formed using a buried oxide layer obtained using an oxygen implantation or SIMOX process. The thickness of this layer can be from, for example, about 1 nm to 100 microns or up to 1 mm or more. 
     In the illustrated example, source region  112  and drain region  110  are formed using layer  106 , which may form a semiconductor channel thin film. By way of one example, layer  106  includes crystalline silicon film. Layer  106  may include, for example, crystalline or amorphous inorganic semiconductor material, such as those used in the regular MOS technologies. Exemplary materials include, but are not limited to, elemental semiconductors like silicon, germanium, graphene, diamond, tin or compound semiconductors like silicon carbide, silicon germanium, diamond, graphite, binary materials like aluminium antimonide (AlSb), aluminium arsenide (AlAs), aluminium nitride (AlN), aluminium phosphide (AlP), boron nitride (BN), boron phosphide (BP), boron arsenide (BAs), gallium antimonide (GaSb), gallium arsenide (GaAs), gallium nitride (GaN), gallium phosphide (GaP), indium antimonide (InSb), indium arsenide (InAs), indium nitride (InN), indium phosphide (InP), cadmium selenide (CdSe), cadmium sulfide (CdS), cadmium telluride (CdTe), zinc oxide (ZnO), zinc selenide (ZnSe), zinc sulfide (ZnS), zinc telluride (ZnTe), cuprous chloride (CuCl), lead selenide (PbSe), lead sulfide (PbS), lead telluride (PbTe), tin sulfide (SnS), tin telluride (SnTe), bismuth telluride (Bi2Te3), cadmium phosphide (Cd3P2), cadmium arsenide (Cd3As2), cadmium antimonide (Cd3Sb2), zinc phosphide (Zn3P2), zinc arsenide (Zn3As2), zinc antimonide (Zn3Sb2), other binary materials like lead(II) iodide (PbI2), molybdenum disulfide (MoS2), gallium Selenide (GaSe), tin sulfide (SnS), bismuth Sulfide (Bi2S3), platinum silicide (PtSi), bismuth(III) iodide (BiI3), mercury(II) iodide (HgI2), thallium(I) bromide (TlBr), semiconducting oxides like zinc oxide, titanium dioxide (TiO2), copper(I) oxide (Cu2O), copper(II) oxide (CuO), uranium dioxide (UO2), uranium trioxide (UO3), 6.1 Å materials, or ternary materials like aluminium gallium arsenide (AlGaAs, AlxGa1-xAs), indium gallium arsenide (InGaAs, InxGa1-xAs), aluminium indium arsenide (AlInAs), aluminium indium antimonide (AlInSb), gallium arsenide nitride (GaAsN), gallium arsenide phosphide (GaAsP), aluminium gallium nitride (AlGaN), aluminium gallium phosphide (AlGaP), indium gallium nitride (InGaN), indium arsenide antimonide (InAsSb), indium gallium antimonide (InGaSb), cadmium zinc telluride (CdZnTe, CZT), mercury cadmium telluride (HgCdTe), mercury zinc telluride (HgZnTe), mercury zinc selenide (HgZnSe), lead tin telluride (PbSnTe), thallium tin telluride (Tl2SnTe5), thallium germanium telluride (Tl2GeTe5) and quaternary like aluminium gallium indium phosphide (AlGaInP, InAlGaP, InGaAlP, AlInGaP), aluminium gallium arsenide phosphide (AlGaAsP), indium gallium arsenide phosphide (InGaAsP), aluminium indium arsenide phosphide (AlInAsP), aluminium gallium arsenide nitride (AlGaAsN), indium gallium arsenide nitride (InGaAsN), indium aluminium arsenide nitride (InAlAsN), copper indium gallium selenide (CIGS), or quinary materials like gallium indium nitride arsenide antimonide (GaInNAsSb), and the like. 
     Layer  106  can also be made of organic semiconducting materials. Examples of such materials include, but are not limited to, polyacetylene, polypyrrole, polyaniline, Rubrene, Phthalocyanine, Poly(3-hexylthiophene, Poly(3-alkylthiophene), α-ω-hexathiophene, Pentacene, α-ω-di-hexyl-hexathiophene, α-ω-dihexyl-hexathiophene, Poly(3-hexylthiophene), Bis(dithienothiophene, α-ω-dihexyl-quaterthiophene, Dihexyl-anthradithiophene, n-decapentafluoroheptylmethylnaphthalene-1,4,5,8-tetracarboxylic diimide, quinquethiophene, N,N′-dioctyl-3,4,9,10-perylene tetracarbozylic, CuPc, Methanofullerene, [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), C60, 3′,4′-dibutyl-5-5bis(dicyanomethylene)-5,5′-dihydro-2,2′:5′,2″terthiophene (DCMT), PTCDI-C5, P3HT, Poly(3,3″-dialkyl-terthiophene), C60-fused N-methylpyrrolidine-meta-C12 phenyl (C60MC12),Thieno[2,3-b]thiophene, PVT, QM3T, DFH-nT, DFHCO-4TCO, BBB, FTTTTF, PPy, DPI-CN, NTCDI, F8T2-poly[9,9′ dioctylfluorene-co-bithiophene], MDMO-PPV-poly[2-methoxy-5-(3,7-dimethyloctyloxy)]-1,4-phenylenevinylene, P3HT-regioregular poly[3-hexylthiophene]; PTAA, polytriarylamine, PVT-poly-[2,5-thienylene vinylene], DH-5T-Dihexylquinquethiophene, DH-6T-α,ω-dihexylsexithiophene, phthalocyanine, α-6T-α-sexithiophene, NDI, naphthalenediimide, F16CuPc-perfluorocopperphthalocyanine, perylene, PTCDA-3,4,9,10-perylene-tetracarboxylic dianhydrid and its derivatives, PDI-N,N′-dimethyl 3,4,9,10-perylene tetracarboxylicdiimide, and the like. 
     Layer  106  may include topological insulator materials such as bismuth antimonide, pure antimony, bismuth selenide, bismuth telluride, antimony telluride, or alternate topological insulator materials known to those familiar with the field of invention. 
     An inversion channel  114  may be formed at a layer  106 -layer  104  interface by controlling a voltage bias applied to substrate  102 , or to a biasing the solution, or both. It is also possible that the inversion channel is formed in layer  106  with no external bias applied to substrate  102 , depending on a doping level in layer  106 , thickness of layer  106 , other such variables, and, for example, a fixed oxide charge density and interface trap states density at its boundaries. The thickness of layer  106  can be from, for example, about 1 nm to 50 microns, depending on the material (e.g., semiconductor material) and its doping density. When biasing substrate  102  to obtain an inversion channel in layer  106 , in one example case, the thickness (t) of layer  106  should be such that the whole thickness of layer  106  should be fully depleted before the formation of inversion channel at layer  106 -layer  104  interface. In another example layer  106  is made very thin, so that it is operated in volume inversion mode. In another example layer  106  is operated in partial depletion mode. In yet another example case layer  106  is operated in depletion mode. In another example case layer  106  is operated in accumulation mode. 
     Layer  106  may include intrinsic or p-type or n-type doped material; correspondingly device  100  can be an n-channel device or a p-channel device, respectively. In exemplary cases, delta doping or implant doping of layer is used. Source region  112  and drain region  110  are formed on either side of the semiconductor layer  106  using known doping techniques. 
     One exemplary layer  106  includes 1 E15 doped p-type silicon layer of thickness between about 10 nm and about 1000 nm. In this case, an inversion layer is formed in the silicon thin film at a silicon (substrate  102 )-buried oxide (layer  104 ) interface by biasing substrate  102 . Alternatively, an accumulation layer may be formed at this interface. Or, volume inversion, accumulation may be formed in layer  106  which may be made less than 100 nm thin. In another example case inversion or accumulation are formed at the top surface of layer  106 , at the layer  106 -layer  108  interface, if present. Exemplary source and drain regions  112 ,  110  are 1 E 19 phosphorous doped N++ regions in this p-type Si channel. 
     Layer  108  may include any suitable dielectric material. A thickness of layer  108  may be between about 2 angstroms and 100 nm. Exemplary materials suitable for layer  108  include inorganic dielectric material that act as a gate dielectric material. Examples include, but not limited to, SiO2, Si3N4, SiNx, Al2O3, AlOx La2O3, Y2O3, ZrO2, Ta2O5, HfO2, HfSiO4, HfOx, TiO2, TiOx, a-LaAlO3, SrTiO3, Ta2O5, ZrSiO4, BaO, CaO, MgO, SrO, BaTiO3, Sc2O3, Pr2O3, Gd2O3, Lu2O3, TiN, CeO2, BZT, BST or a stacked or a mixed composition of these and such other gate dielectric material. 
     Alternatively, layer  108  may include organic monolayers or other gate dielectric materials. Examples include, but are not limited to, PVP-poly (4-vinyl phenol), PS-polystyrene, PMMA-polymethyl-methacrylate, PVA-polyvinyl alcohol, PVC-polyvinylchloride, PVDF-polyvinylidenfluoride, PaMS-poly[a-methylstyrene], CYEPL-cyano-ethylpullulan, BCB-divinyltetramethyldisiloxane-bis(benzocyclobutene), CPVP-Cn, CPS-Cn, PVP-CL, PVP-CP, polynorb, GR, nano TiO2, OTS, Pho-OTS, various self-assembled monolayers or multilayers or a stacked or a mixed composition of these and such other gate dielectric material. 
     Layer  108  can also be made of topological insulator materials such as bismuth antimonide, pure antimony, bismuth selenide, bismuth telluride, antimony telluride, or alternate topological insulator materials known to those familiar with the field of invention. 
     Turning now to  FIG. 2 , a device  200  is illustrated, Device  200  is similar to device  100 , except device  200  includes an additional layer  202  overlying substrate  102  and layers  104 - 108 . 
     Layer  202  may include material to additionally functionalize device  200 . Layer  202  may be, for example, a thin film that is of thickness between 2 angstroms and 100 nm. Although illustrated as a single layer, layer  202  can be a combination of different layers of thin films of different materials. Layer  202  may include, for example, monolayer or multilayer of organic molecules or biomolecules; thin films of semiconducting materials, metals, semi metals, insulators, dielectric materials, meta-materials, or the like that may be additionally used to functionalize the device. 
     Alternately, layer  202  may include multilayers, where first layer is a thin film of one or more materials described above, and a second layer that is made with biological nano or micro pore molecules such as protein nanopore, alpha hemolysin, beta barrel, or DNA base nanopores or other biological or organic molecule based nanopore or micro pores. An exemplary case of layer  202  is when biological nanopore molecule is placed directly on top on layer  106  or layer  108 . Layer  202  may include at least one lipid bilayer overlaying a nanopore or chemical nanopore material. When a device does not include a chemical or biological nanopore material, the device is referred to as a solid-state device, and when the device includes a chemical or biological material, the devices is referred to as a chemical nanopore device or a biological nanopore device. 
     Layer  108  and layer  202  can be deposited using any of the thin film fabrication techniques like sputtering, chemical vapor deposition, physical vapor deposition, epitaxy, atomic layer deposition (ALD), molecular beam epitaxy, e-beam thermal deposition, thermal deposition of other kinds, or any other deposition techniques for thin films or chemical deposition methods of single molecule monolayers or multi-layers. 
       FIGS. 1 and 2  illustrate exemplary devices  100  and  200 . Additional exemplary devices are similar to devices  100  and  200 , except such devices do not include layer  108 . Yet another alternative device  900  is illustrated in  FIG. 9 . Device  900  is similar to device  100  and  200 , except device  900  includes insulating substrate  902  (which may include any of the materials described above in connection with layer  104 ), and layer  904 - 908  overly substrate  902 . Layers  904 - 908  may correspond to layers  106 - 202 , respectively. 
     As set forth above, devices in accordance with various embodiments of the invention may be formed using a variety of materials for the different device layers. The following non-limiting examples illustrate exemplary devices and methods of forming and using the devices in accordance with various embodiments of the disclosure. These examples are merely illustrative, and it is not intended that the invention be limited to the examples. Device in accordance with the present invention may include the compounds and materials listed below as well as additional and/or alternative materials noted herein. 
     SOI Device Structure: 
     In accordance with exemplary embodiments of the disclosure, a device is fabricated on silicon or silicon on insulator (SOI) wafers. Alternately devices in accordance with various embodiments can be fabricated on any semiconductor or semiconductor-on-insulator materials such as GaAS or GaAs on insulator or GaN or GaN on insulator, or other material, as noted above. 
     With reference to  FIGS. 1 and 2 , a device, such as device  100  or  200 , in accordance with these exemplary embodiments, includes a semiconductor channel  124  that is continuous from source region  112  to drain region  110  and which narrows down into a bi-feature point nanopore through substrate  102  at the center. In this case, a silicon gate (in substrate  102 ), which acts as a back/buried-gate, is separated from semiconducting nanopore channel  124  by insulating region  104 , which, in this example, is a gate oxide layer. Source region  112  and drain region  110 , which are n+ doped in this example, may be connected to external instrumentation via bonding pads (e.g., gold) (not shown in schematic). When bias potential is applied to the silicon back-gate of the nanopore transistor, the gate oxide-silicon channel interface is driven into depletion first, followed by full-depletion of the thin film silicon, and then into inversion at the oxide-silicon interface. Inversion channel  114  formed is about 20 nm thin and is continuous along the oxide-silicon interface, from the circular disc of the source through the bi-feature-point-nanopore to the circular disc of the drain. Alternately an accumulation channel may be formed at the gate oxide-silicon channel interface. Or, inversion or accumulation channels may be formed at the top surface of layer  106 . Drain current is measured across the source drain contacts and the devices may be operated at high frequencies from kilo hertz to megahertz to Giga hertz switching (speed is generally inversely proportional to gate oxide thickness). Thus, measurements of individual molecular translocation events up-to and above 100,000 events per second may be obtained using these devise. 
     Electric Field Focusing and Coupling Amplification: 
     At the nanopore point location electric field focusing occurs due to feature curvature convoluted around the nanopore center. It is verified theoretically and experimentally that electrostatic field varies directly with surface curvature of an object, and electrostatic field extrema along an equipotential contour correspond to curvature extrema. And in specific case of 3D feature (e.g., conical or pyramidal) geometry field intensity characteristics approach a singularity with not just field intensity extrema but surface charge, potential, density of state and surface state interaction extrema occurring at such feature point geometries. In the exemplary MOSFET devices, electric field focusing is even more extreme due to the nano scale surface convoluted around the nanopore center. These amplified fields, states and interactions at the point nanopore location are then coupled to the exponentially transducing FET device structure. The response resulting from these double amplification events is read at above kilo/Megahertz frequencies via source-drain inversion channel current. While the simulations below illustrate a perfect bi-conical nanopore, this is only an exemplary case, and the device may have a single feature nanopore or an imperfect bi-feature (e.g., conical or pyramidal) nanopore. 
     Device Performance Characteristics &amp; Simulation: 
     In exemplary devices, frequency of nanopore-potential coupling is generally related to thin dielectric film (high capacitance) and fully depleted silicon film thickness (design variable). 1/f noise is not a problem at these high frequencies. To validate device response to nanopore-potential variation, we performed preliminary 2D simulations using ATLAS (Silvaco) software. An 8 nm FET nanopore device is defined to scale—using tools available in Atlas. DNA Translocation is modeled by varying potential applied to FGate (Floating gate at nanopore center), and FET device response is simulated.  FIG. 7  shows 1 nano-ampere inversion current response to 0.01 V variation in floating gate (nanopore) potential. SIMOX (separation of substrate  102  and layer  106  by implantation of oxygen) MOSFETs exhibit good sub-threshold characteristics even in ionic buffer solutions, with currents in pico ampere range. Hence nano-ampere inversion response results in noise ratios as high as 100. A sub-milli volt (to micro-volt) potential variation (mimicking an AC signal on a DC bias) due to DNA base translocation, coupled by other chemical or biological methods described herein, will be amplified first by field-focusing at the bi-feature nanopore, which is then exponentially coupled to inversion (or accumulation channel) channel-producing tens of picoampere to a few nanoampere range inversion current variation which is readily readable with high signal to noise ratios, enabling potential fast sequencing of DNA. Further, redundancy of device response for high quality sequencing is achieved by redundant combinatorial detection arrays based on complementary CMOS technology. 
     Exemplary Methods of Fabrication: 
     Chemical-Stop Nanopore Etching for Controlled Nanopore Diameter (10 nm to 1 nm): 
     Fabrication of nanopores in silicon by chemical etching using KOH and KCl with electrical feedback has been demonstrated to yield nanopores of controlled diameter.  FIG. 3  illustrates an improved, nanopore fabrication process for precise control of nanopore diameter—e.g., for forming etch region  118 . Etched region may be formed on one or both sides of the substrate layer. In the illustrated example, a silicon substrate  302  is masked with an e.g., a silicon nitride mask  304  (e.g., about 200 nm), having an opening  306  therein. The masked substrate is then exposed to a first etch solution to form an etch region  308 . The structure is then exposed to a second etch solution to form second etch region  310 . 
     The fabrication process illustrated in  FIG. 3  is based on the chemical-stop etching. Such techniques generally yield either pyramidal holes or circular-conical holes; an exemplary pyramidal hole is illustrated in  FIG. 6 , which show an etched feature  308  (or portion thereof) though a substrate. The principle idea is to stop base-etching of the silicon nanopore at the nanopore-location, once nanopore etch-through has occurred, by way of using an acidic buffer solution (or weak acidic solutions) at the other end of the silicon film. When base-etchant (e.g., tetramethylammonium hydroxide (TMAH) or KOH) etches through the thin silicon membrane, forming a sub-10 nm nanopore, OH −  radicals from base etchant instantly meet H +  radicals from acidic buffer solutions on other side, forming water molecules and salt. Consumption of OH −  radicals at the nanopore interface leads to instantaneous stopping of any further etching of nanopore. Using a feedback electrical sense circuit  312 , to measure conduction across the nanopore due to base-acid neutralization, any further etching of nanopore is stopped. This two-step etch-stop process: chemical etch-stop combined with electrical feedback etch-stop is expected to yield much higher control of nanopore fabrication. This chemical-stop etch process can be used for fast, precise fabrication of controlled nanopores in many different kinds of substrate materials. Neutralization reaction at the nanopore is an exothermic process. Hence weak acidic buffer solutions (˜pH from 2 to 6) are used, where acidic buffer pH value, its buffer capacity and TMAH concentration may be process variables. 
     Capacitance and Resistance Based Measurements for Residual Silicon Thickness: 
     Using CV measurements in addition to resistance/conductance measurement, can be used to monitor the residual thickness of silicon film while it is being etched. With decreasing silicon thickness, as it is etched, the capacitance of silicon at the nanopore location is expected to vary (increase), which can be measured and correlated. 
     Another Method for Nanopore Fabrication: 
     Backside of the substrate can be coated with a metal or semiconducting conducting layer thin film, and the conductivity (or capacitance) between the solution on etching side and this back conducting film is monitored with time. When a nanopore is formed on the substrate, the etching fluid comes into contact with back metal or conductive film, which causes a large change in conductivity or capacitance or impedance. By measuring conductivity (or capacitance or impedance) at high frequency voltage bias, and stopping the etch reaction when the conductivity changes, very accurate nanopores (e.g., having defined features such an a size of an opening) can be formed. 
     Alternate Methods for Nanopore Fabrication: 
     Alternatively, nanopores can be fabricated using methods and instruments such as electron beam milling, FIB (focused ion beam), ion beam sculpting, or other suitable technique. 
     Additionally, a nanopore (or a micro pore) once formed might be narrowed or shrunk down (i.e., its diameter at the opening reduced) further by growing an additional layer such as thermal silicon dioxide. Or, a nanopore can be shrunk/narrowed using electron beam techniques or ion beam/laser based or other local thermal heating based methods. 
     Methods of making nanopores, both solid state and biological nanopores, are listed in the following publications, which are included herein by their reference in their entirety, to the extent their contents do not conflict with the present disclosure.
       Nanopore sensors for nucleic acid analysis, Bala Murali Venkatesan  &amp;  Rashid Bashir Nature Nanotechnology,  6, 615-624 (2011), doi: 10.1038/nnano.2011.129.     Disease Detection and Management via Single Nanopore - Based Sensors  Reiner, Joseph E.; Balijepalli, Arvind; Robertson, Joseph W. F.; et al. CHEMICAL REVIEWS Volume: 112 Issue: 12 Pages: 6431-6451 DOI: 10.1021/cr300381m December 2012.     Single molecule sensing with solid - state nanopores: novel materials, methods, and applications  Miles, B N (Miles, Benjamin N.)[1]; Ivanov, A P (Ivanov, Aleksandar P.)[1] et al. CHEMICAL SOCIETY REVIEWS Volume: 42 Issue: 1 Pages: 15-28 DOI: 10.1039/c2cs35286a 2013.     Electron - beam - induced deformations of SiO 2  nanostructures  Storm, A J (Storm, A J); Chen, J H (Chen, J H); Ling, X S (Ling, X S); Zandbergen, H W (Zandbergen, H W); Dekker, C (Dekker, C) JOURNAL OF APPLIED PHYSICS Volume: 98 Issue: DOI: 10.1063/1.1947391 Jul. 1, 2005.   

     Self-Aligned Nanopore Fabrication: 
       FIG. 4  illustrates one exemplary structure for nanopore device fabrication, which includes a “self-aligned mask formation” on the bottom-side for single or double nanopore (e.g., conical, pyramidal, or the like) formation. The double etched-feature structure serves two purposes: (1) towards formation of nanopore point location for high sensitive FET signal transduction and (2) self-aligned mask on the double structure is desired for fabrication of self-aligned implantation-barrier masks on both sides for oxygen ion implantation, for buried oxide formation. Fabrication of a self-aligned mask is done by, for example, taking advantage of UV transmittance through, e.g., sub-500 nm silicon membranes. Other than trace UV transmittance, infrared-lithography, x-ray lithography and e-beam patterning techniques may also be used. Alternately, a sub-100 nm nanopore (or a sub-micron pore) may be formed first, and a self-aligned mask may be formed by using the UV light (or e-beam or X-ray light) transmitted out of the nanopore to pattern resist coated on the other side. The nanopore so formed may be shrunk/narrowed by, for example, depositing a thin film, growing a thermal film or using e-beam/thermal induced deformations. 
     To form the double nanopore, an etch feature (e.g., conical, inverted pyramid, or the like)  408  (˜1.5 μm) is etched into patterned SOI substrate  402  (˜2 μm) using a mask (e.g., SiN)  404 , having an opening  406 . Following this, positive UV photo-resist  410  is spun on the back side of the wafer (on top of nitride thin film). Due to UV transmittance through thin silicon films or using UV transmittance through nanopore, back side resist is exposed by UV incidence on front side, to yield self-aligned resist window  412 , symmetric to top etch area  408 . Alternately self-aligned mask is produced by using nanoparticles or beads at in the etched areas as mask. Or patterning masks using focused ion beam or scattering deposition or e-beam deposition or other techniques may be used. The self-aligned mask formed on both sides is used as mask for SIMOX oxygen implantation. After buried oxide formation by implantation, using nitride film  404  as base-etch mask, as shown in  FIG. 4 , chemical-stop nanopore fabrication technique is used to realize self-aligned single or double nanopore  414 . 
     Double-Feature Nanopore on Silicon on Insulator (SOI, 1 to 1000 μm Thin Film): 
     When SOI substrates are used as base material for device fabrication, the back of the substrate silicon may be etched away along with the buried oxide (BOX) layer, and the device nanopore is realized on the SOI thin film, which is approximately 1 to 2000 micron thick. In one exemplary case, the thickness of initial SOI film is in between 2 micron to 1000 micron. 
     Self-Aligned Oxygen Implantation Mask Fabrication: 
     Alternately, self-aligned oxygen implantation mask can be fabricated by first depositing an oxygen implantation mask layer such as nitride, chrome thin film, followed by photo-resist spinning. Photo resist, due to being viscous liquid, will fill the feature (e.g., conical or inverted pyramidal structures). After soft-baking the photo resist the wafer is treated to oxygen plasma where most of the photo-resist on the top is completely etched away, only photo resist in the recessed areas survives. The Chrome thin film is etched with patterned resist as a mask. The chrome layer is then used as etch-mask for nitride-etch in a reactive ion etch process. 
     Oxygen Implantation and Annealing for Buried Oxide: 
     With reference to  FIG. 5 , once a single or double structure  502  is formed, nitride masks  504 ,  506  for oxygen implantation are formed. Oxygen implantation layer  508  will isolate the silicon channel  510  from the silicon buried gate  512  that is used to bias the channel into inversion, accumulation or depletion, desired for device exponential coupling. Following oxygen implantation and the subsequent annealing steps, to yield buried oxide double layer, the wafer is ready for photo patterning.  FIG. 10  illustrates an etch feature or structure  308  formed though a substrate including a buried or substrate silicon layer  602 , buried oxide layer  604 , and a top semiconductor layer  606 , according to this technique. 
     The following publication discussing SIMOX implantation and buried oxide formation on silicon wafers and etched silicon wafers is included here in its entirety by reference.
     Fabrication of [110]-aligned Si quantum wires embedded in SiO2 by low-energy oxygen implantation Yukari Ishikawa a, N. Shibata S. Fukatsu Nuclear Instruments and Methods in Physics Research B 147 (1999) 304±309   

     Photo Patterning and Defining of Device: 
     Once the various pores and layers are formed, photo patterning is used to isolate and/or provide access to each of the three layers-buried silicon gate  512  that is sandwiched between buried oxide layer  508 ; buried oxide layer  508  acting a gate oxide for the FET device; the silicon channel is then patterned using conventional lithography (on both sides) to open windows in nitride mask layers, followed by n+ doping to form source region  514  and drain region  516  on either side of structure  518 . Metal contacts may then be formed to the source  514 , drain  516  and the buried gate regions  508 —to realize a functioning MOSFET device. 
     ALD Conformal Dielectric Coating on FDEC Nanopore Active Device Surface: 
     To achieve high control of surface states at the Top silicon-oxide interface, the native oxide is replaced by select dielectric materials that are coated using atomic layer deposition in conformal fashion. 
     Characterization and testing, process improvements for 1 MHz operational devices: 
     Standard n-MOS characterization and processing optimization steps are used to improve device performance characteristics. 
     Other Methods of Nanopore Fabrication: 
     Formation of top semiconductor film of device using MBE, CVD or other techniques can be done as follows:
         Step 1: Fabricate a nanopore in silicon or any semiconductor material or any conductor material.   Step 2: Deposit or grow or coat the above nanopore device with oxide or nitride or any other CMOS related dielectric material as defined in previous section.   Step 3: Deposit or grow or coat another crystalline or poly-crystalline or amorphous semiconductor material film or metal material film or insulator material film on top of the above structure.   Step 4: Use this structure as a FET structure, by forming source drain regions if needed, which can be used to sense the translocation of biomolecules (such as proteins or DNA) passing through the nanopore as described in the rest of the application or other materials as noted herein.       

     The methods described herein may also include forming at least one lipid bilayer overlaying a nanopore and/or adding a biological and/or chemical substance to the structure to form a biological and/or chemical nanopore. 
     Method of Using the Device: 
     The devices described herein can be used to detect and characterize a variety of materials, including organic molecules, ionic species, nanoparticles, molecular species, materials selected from the group consisting of a DNA molecule, a protein molecule, a peptide molecule, a polypeptide molecule, an RNA molecule, a synthetic oligo nucleotide molecule, and a synthetic peptide or polypeptide molecule, or a combination of these materials, and any of these materials modified with at least one tag selected from the group consisting of metal species, metal-organic species, chemical modifiers, biomolecular tags, complementary hybridizing chain molecules, peptides, polypeptides, oligonucleotides, zinc fingers, nano particles, quantum dots, organic dyes, beads, nanowires, and nanotubes. 
       FIG. 8  illustrates a device  800 , including a substrate  802 , an etch region  804 , an insulating region  806 , a source region  808  formed overlying insulating region  806  and overlying a first surface of the substrate  802 , and a drain region  810  formed overlying insulating region  806  and overlying a first surface of the substrate. During operation of device  800 , material  812  to be detected and/or characterized passes through a nanopore  814  of device  800 . 
     Methods for Sequencing: 
     (a) Sequencing of Unmodified ssDNA: 
     As discussed in the previous sections, devices as described herein can be operated as sensor in different modes of operations, viz potential coupled mode and charged coupled mode. Base charge induced potentials on nanopore capacitor electrodes on the order of a milli volt have been reported in literature, varying between bases in magnitude and spatial distribution, calculated in response to external applied fields in a nanopore capacitor. Potential variation on the order of few hundred micro volts to milli volts should be detectable by operation of a device as described herein in potential coupled mode (device has very less defect states). A DNA nucleotide translocating at high speeds of microseconds per base through a nanopore constriction of few nm in diameters, sees an AC signal at 100 K to 1M Hz frequencies and an amplitude of few hundred micro volts. Such potential variation will be amplified at an edge of the nanopore, and further by the device coupling with the inversion channel. Device coupling with inversion or accumulation channel may be exponential in fully depleted films. An FET device operating at or above 10 MHz frequencies with internal amplification factor (combined amplification due to nanopore-curvature field and device coupling) is expected to be able to detect an unmodified DNA nucleotide passing at mega base per second speeds. 
     The above mentioned potential variation during translocation through a nanopore device is associated with charge variations, more specifically dipole variations between individual bases. Such charge, dipole variations can be read by a device in accordance with the present disclosure in charge coupled mode. We have demonstrated using a planar device charge, dipole coupling sensitivity up to few parts per trillion in gaseous phase detection of amine ligation. Using a device in accordance with the present disclosure, one expects charge coupling to be amplified further, with higher selectivity of base readout. But the read out speed in charge coupling mode is limited by interface trap state coupling speed which is in milli second time scales. Hence device charge coupling is slower than device potential coupling by orders of magnitude. 
     The present methods may be used on modified DNA nucleotides and on unmodified DNA. 
     (b) Sequencing by Hybridization: 
     In accordance with various embodiments of the disclosure, a method uses ssDNA hybridized with 7-mer probe strands. As one example, the 7-mer probe strand will consist of a combination of 4-mer combinatorial base sequences and a 3-mer universal base common to all combinations. Using this approach, translocation of a lengthy DNA strand with discrete probe hybridized regions, passing through the nanopore at mega base per second speeds, is detectable with much higher sensitivity compared to a unmodified DNA strand. This would then need a total of 4 4  (256) separate probe hybridized translocation experiments for sequencing of a full genome. 
     (c) Sequencing of Chemically Modified ssDNA: 
     Another method of investigation for optimized potential and charge transduction using a device in accordance with the present disclosure is chemical modification of DNA strands in base selective fashion. Chemical modifications can use charged species or bulk moieties such as base selective DNA, organic molecule, peptide, protein molecules or metal or metal-organic moieties. Such base specific modification on single stranded DNA enables sequencing via translocation through use of devices of the present disclosure. Examples of chemical modification of bases are: Translocation of RecA-coated double-stranded DNA through solid-state nanopores; chemical modification of thymine-osmium oxidation of thymine; detection of methylated cytosine as one approach to cytosine sequencing; or cytosine can be chemically labeled and sequencing by sulphonation followed by deamination; chemical modification of guanine-methylene-blue sensitized photo-oxidation of guanine can be used to selective sequence guanine occurrence in the DNA strand. 
     High Fidelity DNA sequencing using RCDAs: 
     Devices in accordance with exemplary embodiments of the disclosure can be designed, fabricated and operated as n-channel devices or as a p-channel devices with a hole inversion layer formed at, for example, the oxide-silicon channel interface. Since fabrication of these devices may be based on CMOS VLSI technology, it is possible to fabricate both n-channel and p-channel devices side-by-side with a few hundred micron spacing between them. 
     The purpose of having both n-channel and p-channel device nanopores is that their respective responses to potential and charge variations at the point nanopore location will be in opposite directions. A small increase in potential applied to sensitive surface of an n-channel device sensor produces an increase in inversion current (decrease in threshold voltage). Similar increase in potential produces a decrease in p-channel FDEC FET sensor. A time varying potential due to high speed molecular transport events through the nanopore, or equivalently, a small (μV to nV) oscillating AC signal produces an amplified oscillating signal measured across source and drain, with opposite responses (i.e., 180 phase shifts) from n-channel and p-channel FDEC devices. 
     Furthermore amplified sensing along similar lines is expected to happen when the semiconductor channel is biased into accumulation. An n-channel FET nanopore can be operated in FDEC inversion coupled mode or in amplified accumulation coupled mode, by simply biasing the gate at either ends of the Id-Vg curve. Alternately inversion or accumulation can be formed at the top surface of semiconductor film at the interface with solution, and the conductivity in this case can be modulated by changing the solution bias. 
     Each device may be fabricated in parallel with complementary p-channel and accumulation biased devices (along with few other possible variations). Each DNA segment may be sequenced simultaneously, with integrated microfluidics, using each of these different FET nanopore device transduction mechanisms. This will provide robust redundancy for attaining ultra-high fidelity DNA sequencing. Such arrays are termed redundant combinatorial detection arrays (RCDA). 
     Every formulation or combination of components described or exemplified can be used to practice the invention, unless otherwise stated. Specific names of compounds are intended to be exemplary, as it is known that one of ordinary skill in the art can name the same compounds differently. One will appreciate that methods, device elements, starting materials, and synthetic methods, other than those specifically exemplified can be employed in the practice of the invention without resort to undue experimentation. All art-known functional equivalents, of any such methods, device elements, starting materials, and synthetic methods, and are intended to be included in this invention. Whenever a range is given in the specification, for example, a temperature range, a time range, or a composition range, all intermediate ranges and sub ranges, as well as all individual values included in the ranges given are intended to be included in the disclosure. When a Markush group or other grouping is used herein, all individual members of the group and all combinations and subcombinations possible of the group are intended to be individually included in the disclosure. 
     The present invention has been described above with reference to a number of exemplary embodiments and examples. It should be appreciated that the particular embodiments shown and described herein are illustrative of the invention and its best mode and are not intended to limit in any way the scope of the invention. It will be recognized that changes and modifications may be made to the exemplary embodiments without departing from the scope of the present invention. These and other changes or modifications are intended to be included within the scope of the present invention.