Abstract: A given planarity of the underlying layer is ensured after removal of a porous layer. In the first step, a porous layer is filled with a preprocess solution (e.g., water). In the second step, the preprocess solution filling the porous layer is replaced with an etchant (e.g., fluoric acid), and the porous layer is etched by the etchant. With this process, the time in which the porous layer is filled with the etchant is shortened to suppress variations in progress of etching.

Abstract: The invention relates to a method for making a relief strip, comprising the steps of etching the strip, causing the etched strip to pass through a coloring line, a silicone solution metering unit, to meter a silicone solution on the strip etched portion, introducing the strip into a mold having a plurality of mold cavities of different cross-sections and spacings, therefrom a vacuum metered ink amount is ejected and caused to enter the recess of the material, and causing the strip to further pass through an infrared oven, and finally brushing the strip.

Abstract: In the production or a shadow mask, the through-holes for passing an electron beam are formed by etching of the Fe—Ni alloy. The variation in diameter of apertures is prevented by dispersing 2000 or more of precipitates and inclusions from 0.01 &mgr;m to 5 &mgr;m in diameter on the surface of said material per mm2. The Fe—Ni alloy of from 34 to 38% of Ni, not more than 0.5% of Mn, and if necessary, from 5 to 40 ppm of B, and from 5 to 40 ppm of N, the balance being Fe and unavoidable and incidental impurities with the proviso of 0.10% or less of C, 0.30% or less of Si, 0.30% or less of Al, 0.005% or less of S, and 0.005% or less of P.

Abstract: The stamping process and a method of fabrication of nano-stamps with characteristic dimensions below 1 nm and up to 100 nm intended for usage in making patterns of characteristic dimensions the same as those of the nano-stamp on surface of a substrate is provided. In the process a very hard stamp is fabricated by first depositing alternating layers of two materials, one of which has very high hardness, on some sacrificial substrate via PVD, CVD or any other deposition procedure that produces alternating layers of selected thickness, from sub 1 nm to above 100 nm. The layered film is then polished to an atomically smooth finish perpendicular to the plane of the layers and etched to produce dips in the softer layers. These steps produce a grid of parallel elevations and valleys on the etched surface, which now can be used as a stamp to stamp out patterns on a substrate of lower hardness than the hardness of the elevated layers.

Abstract: Method for removing a portion of the binder phase from the surface of a substrate that is composed of particles of at least a first phase joined together by the binder phase, and wherein the surface is etched by contacting it with a gas flow of an etchant gas and a second gas. The second gas is one or more gases that will not react with the substrate or the removed binder phase and will not alter the oxidation state of the substrate during etching.

Abstract: A method for producing a porous diamond according to the present invention comprises steps of forming an anodized alumina layer, which functions as a mask, on a diamond substrate; and performing a plasma etching treatment to form pores on the diamond substrate, which pores have the same arrangement as those of the anodized alumina mask.

Abstract: One embodiment of a microneedle array is constructed of silicon and silicon dioxide compounds using MEMS technology and standard microfabrication techniques to create hollow cylindrical individual microneedles. The resulting array of microneedles is designed to penetrate the stratum corneum and epidermis layers of skin, but not into the dermis. In a second embodiment, an array of hollow (or solid) microneedles are constructed of molded plastic, in which a micro-machining technique is used to fabricate the molds used in a plastic microforming process. Such molds contain a micropillar array and/or microhole array. The manufacturing procedures for creating plastic arrays of microneedles include: “self-molding,” micromolding, microembossing, and microinjection techniques. In the “self-molding” method, a plastic (e.g.

Abstract: A polycrystalline diamond member and a method for making the same. The member includes a backing and a layer of polycrystalline diamond on the backing wherein the layer of polycrystalline diamond has a rake surface and a flank surface. The layer of polycrystalline diamond has an interior region adjacent to the backing and an exterior region adjacent to the interior region wherein the exterior region terminates at the rake surface. The interior region includes interior diamond particles and a catalyst with the interior diamond particles being bridged together so as to form interstices therebetween. The catalyst is at the interstices of the interior diamond particles. The exterior region includes exterior diamond particles bridged together so as to form interstices therebetween with the exterior region being essentially free of the catalyst. A chemical vapor deposition-applied hard material essentially surrounds the exterior diamond particles.

Abstract: A technique to prevent peeling of deposits formed on the surface of the inner walls of the thin-film formation apparatus and the members inside the apparatus and to suppress particle production without contamination of the inside of the apparatus. A member for a thin-film formation apparatus having inner walls and a method for manufacturing the member is provided. A plurality of unevenness is provided on at least a portion of the surface of the member and the inner walls on which unnecessary thin films are deposited. The surfaces are subjected to masking, and then, etching processing to form the plurality of unevenness. After the etching processing the masking is removed.

Abstract: A microneedle array is constructed of silicon and silicon dioxide compounds using MEMS (i.e., Micro-Electro-Mechanical-Systems) technology and standard microfabrication techniques. The microneedle array may be fabricated from a silicon die which can be etched in a microfabrication process to create hollow cylindrical individual microneedles. The resulting array of microneedles can penetrate with a small pressure through the stratum corneum of skin (including skin of animals, reptiles, or other creatures—typically skin of a living organism) to either deliver drugs or to facilitate interstitial fluid sampling through the hollow microneedles.

Abstract: A method of making a connection component for a microelectronic element includes providing a sheet comprising an electrically conductive layer, a photoresist layer overlying the conductive layer and a photoimageable dielectric layer disposed under the conductive layer. The method includes lithographically forming at least one opening in the photoresist layer to uncover a portion of the conductive layer, forming a plurality of circuit features from the conductive layer by removing the uncovered portion of the conductive layer, at least some of the circuit features being leads, and lithographically forming at least one aperture in the photoimageable dielectric layer.

Abstract: A method of manufacturing a shape memory alloy ink jet printhead wherein an array of nozzles are formed on a substrate utilizing planar monolithic deposition, lithographic and etching processes. Multiple ink jet heads are formed simultaneously on a single planar substrate such as a silicon wafer. The printheads can be formed utilizing standard VLSI/ULSI processing and can include integrated drive electronics formed on the same substrate. The drive electronics preferably being of a CMOS type. In the final construction, ink can be ejected from the substrate substantially normal to the substrate plane.

Abstract: A method for forming an ink jet nozzle plate includes providing a structure having a top substrate layer, a bottom substrate layer, and a buried layer disposed between the top substrate layer and the bottom substrate layer; providing a composite mask over the top substrate layer having a cavity mask which provides openings and a bore mask having openings which are entirely within the openings of the cavity mask and extend to the top substrate layer; anisotopically etching through the bore mask openings through top substrate layer and the buried layer into a portion of the bottom substrate layer; removing the bore mask and etching the top and bottom substrate layers without substantially affecting the buried layer to extend the openings in the top substrate layer and the bottom substrate layer; removing the cavity mask and attaching the top substrate layer to a base provided with ink delivery channels with correspond to the openings in the buried layer; and removing the bottom substrate layer.

Abstract: A substrate on which a plurality of thin films having a plurality of cross-sections corresponding to the cross-section of a micro-structure are formed is placed on a substrate holder. The substrate holder is elevated to bond a thin film formed on the substrate to the surface of a stage, and by lowering the substrate holder, the thin film is separated from the substrate and transferred to the stage side. The transfer process is repeated to laminate a plurality of thin films on the stage and to form the micro-structure. Accordingly, there are provided a micro-structure having high dimensional precision, especially high resolution in the lamination direction, which can be manufactured from a metal or an insulator such as ceramics and can be manufactured in the combined form of structural elements together, and a manufacturing method and an apparatus thereof.

Abstract: This invention relates to processes for the assembly of three-dimensional structures having periodicities on the scale of optical wavelengths, and at both smaller and larger dimensions, as well as compositions and applications therefore. Invention embodiments involve the self assembly of three-dimensionally periodic arrays of spherical particles, the processing of these arrays so that both infiltration and extraction processes can occur, one or more infiltration steps for these periodic arrays, and, in some instances, extraction steps. The product articles are three-dimensionally periodic on a scale where conventional processing methods cannot be used.

Abstract: This invention relates to processes for the assembly of three-dimensional structures having periodicities on the scale of optical wavelengths, and at both smaller and larger dimensions, as well as compositions and applications therefore. Invention embodiments involve the self assembly of three-dimensionally periodic arrays of spherical particles, the processing of these arrays so that both infiltration and extraction processes can occur, one or more infiltration steps for these periodic arrays, and, in some instances, extraction steps. The product articles are three-dimensionally periodic on a scale where conventional processing methods cannot be used.

Abstract: A method for preparing a semiconductor member comprises: forming a substrate having a non-porous silicon monocrystalline layer and a porous silicon layer; bonding another substrate having a surface made of an insulating material to the surface of the monocrystalline layer; and etching to remove the porous silicon layer by immersing in an etching solution.

Abstract: A substrate on which a plurality of thin films having a plurality of cross-sections corresponding to the cross-section of a micro-structure are formed is placed on a substrate holder. The substrate holder is elevated to bond a thin film formed on the substrate to the surface of a stage, and by lowering the substrate holder, the thin film is separated from the substrate and transferred to the stage side. The transfer process is repeated to laminate a plurality of thin films on the stage and to form the micro-structure. Accordingly, there are provided a micro-structure having high dimensional precision, especially high resolution in the lamination direction, which can be manufactured from a metal or an insulator such as ceramics and can be manufactured in the combined form of structural elements together, and a manufacturing method and an apparatus thereof.

Abstract: A system and method for decapsulating a chip-scale package having a first width are disclosed. The method and system include coupling the chip-scale package to a substantially rigid receptacle. The receptacle has a second width and a periphery. The second width is larger than the first width. The chip-scale package does not extend to the periphery of the receptacle. The method and system further include holding the receptacle in proximity to the periphery and decapsulating the chip-scale package.

Abstract: A process for planarization of a silicon wafer is described together with apparatus for implementing it. The process planarizes by directing a high-energy, pulsed laser beam in a direction parallel to the wafer surface while the wafer is rotating. The height of the beam relative to the wafer is carefully controlled thereby enabling the removal of all material above the lower edge of the beam to be removed from the wafer through laser ablation. The method works equally well for removal of metal (as in planarization of damascene wiring) or dielectric (as in planarization of conventional wiring). Once all excess material has been removed (typically requiring about 60 seconds) additional operation of the process does no harm so neither end point detection nor precise control of process time are required.

Abstract: A method for preparing a semiconductor member comprises: forming a substrate having a non-porous silicon monocrystalline layer and a porous silicon layer; bonding another substrate having a surface made of an insulating material to the surface of the monocrystalline layer; and etching to remove the porous silicon layer by immersing in an etching solution.

Abstract: The pore-size distribution of a porous sample of variable porosity is modeled achievement of, allowing laboratory studies on the behavior of the medium modeled in relation to fluids. The porosity of the porous medium is modeled on one or more parting surfaces by means of a network (R) of intersecting channels (C) whose nodes form pores (P), the size of these channels showing physical properties of the medium and being selected from one or more discrete channel size distributions. In order to model the porosity of a heterogeneous sample exhibiting very different porosity zones, several discrete channel distributions are preferably used, these distributions being disjoint or not, and modeling with different zones, zones of low permeability and zones of higher permeability.

Abstract: Method for removing a portion of the binder phase from the surface of a substrate that is composed of particles of at least a first phase joined together by the binder phase, and wherein the surface is etched by contacting it with a gas flow of an etchant gas and a second gas. The second gas is one or more gases that will not react with the substrate or the removed binder phase and will not alter the oxidation state of the substrate during etching.

Abstract: Apparatus for optical analysis of a sample material includes a channel block incorporating microfabricated channels and an integral gel material. Illuminating optics direct light to the sample material and light reflected from, refracted by and/or emitted by the sample is collected by collection optics for detection. The gel material is formed within the channels and includes multiple closely spaced pillars to form a porous separator for sample material to be analyzed.

Abstract: A method of forming an internal channel within an article, such as a cooling channel in an air-cooled blade, vane, shroud, combustor or duct of a gas turbine engine. The method generally entails forming a substrate to have a groove recessed in its surface. A solid member is then placed in the groove, with the solid member being sized and configured to only partially fill the groove so that a void remains in the groove. The void is then filled with a particulate material so that the groove is completely filled. A layer is then deposited on the surface of the substrate and over the solid member and the particulate material in the groove, after which at least the solid member is removed from the groove to form the channel in the substrate beneath the layer.

Abstract: A silicon-based carrier matrix having a high ratio of surface area to volume is intended for use in integrated microanalysis systems. The carrier matrix comprises at least one layer of microporous silicon on a body of monocrystalline silicon. A method for producing the carrier matrix comprises electrochemical etching of a body of monocrystalline silicon, thereby to form at least one layer of microporous silicon on this body. The use of the carrier matrix for chemical sensors in integrated microanalysis systems, as well as in various sorts of chromatography, is also disclosed.

Abstract: The invention relates to a method for treatment of liquid, that is meant particularly for filtering of pressurized liquid, such as water led from a water distribution system, by way of an apparatus, which has an essentially closed frame (1), in connection with which there has been arranged at least a filtering device (2) for purifying of liquid and a flow device (3), such as feed-flow and/or exhaust flow arrangements (3a, 3b) for leading of liquid. The filtering device (2) is made of thin filtering film (2a), advantageously made of plastic based material, such as PTM (Particle Track Membrane), TeM (Track-etch Membrane) or like, the thickness of which is preferably 7-25 &mgr;m and the size of pores of which is 0.05-10 &mgr;m. The filtering film (2a) belonging to a filtering device (2) are being purified essentially self-powered, such as by way of a purification device (5) exploiting the pressure (p) or the movement (v1) of the liquid to be treated and/or the liquid that has been treated.

Abstract: The present invention relates to an improved photolithography process particularly suitable for high-resolution optical lithography techniques using the g, h and i lines of the spectrum of mercury and short-wavelength UV, comprising, prior to deposition of the photosensitive resin on the layer of material to be lithographically patterned, the formation of an antireflective porous layer within the said layer to be lithographically patterned and on the surface of the latter.

Abstract: A method for preparing a semiconductor member comprises: forming a substrate having a non-porous silicon monocrystalline layer and a porous silicon layer; bonding another substrate having a surface made of an insulating material to the surface of the monocrystalline layer; and etching to remove the porous silicon layer by immersing in an etching solution.

Abstract: The present invention provides an electron-beam cell projection aperture formation method comprising: a step of applying a converged ion beam to a top surface of a substrate so as to be etched to a depth enabling to obtain a sufficient film thickness for absorbing or scattering an electron-beam thereby to form an opening of a desired pattern on the top surface; and a step of uniformly applying the converged ion beam to a back surface of the substrate, excluding a hem portion thereof, so as to be etched to a depth reaching the opening.

Abstract: The invention provides a method of producing a through-hole, a substrate used to produce a through-hole, a substrate having a through-hole, and a device using such a through-hole or a substrate having such a through-hole, which are characterized in that: a through-hole can be produced only by etching a silicon substrate from its back side; the opening length d can be precisely controlled to a desired value regardless of the variations in the silicon wafer thickness, and the orientation flat angle, and also regardless of the type of a silicon crystal orientation-dependent anisotropic etchant employed; high productivity, high production reproducibility, and ease of production can be achieved; a high-liberality can be achieved in the shape of the opening end even if temperature treatment is performed at a high temperature for a long time; and a high-precision through-hole can be produced regardless of the shape of a device formed on the surface of a substrate.

Abstract: A method for fabricating a filter element to prevent contaminants from entering an ink supply inlet of an ink jet printhead. The filter is formed by laser ablation process in which output laser radiation is directed through a mask system or light transmitting system to create a filter hole pattern in a thin film. Slightly tapered holes are formed in the film, and the formed filter element is laminated to the ink supply inlet. The tapered holes provide improved flow/impedance and add increased structural strength.

Abstract: A method of manufacturing a magnetic head slider from a flying surface pattern formed on one surface of a long and slender rectangular parallelepiped slider block having a plurality of thin film magnetic head elements aligned in a row. The method includes preparing an arrangement jig including a guide plate and an adhesive rubber plate which adheres onto a lower surface of the guide plate by its adhesive force. The method also includes placing blocks in the accommodation holes on the guide plate in such a manner that the surface of each block on which a pattern is formed is directed upward and each block is fixed by the adhesive force of the rubber plate. The rubber plate is then peeled off after an upper surface of the arrangement jig has been set upside down. Pouring and penetrating hardening liquid into clearances formed between the accommodation holes on the guide plate and the blocks is the next step. The guide plate is then fixed onto a base plate and a pattern is formed on the surface of each block.

Abstract: A glass or metal wire is precisely etched to form the paraboloidal or ellipsoidal shape of the final desired capillary optic. This shape is created by carefully controlling the withdrawal speed of the wire from an etchant bath. In the case of a complete ellipsoidal capillary, the etching operation is performed twice in opposite directions on adjacent wire segments. The etched wire undergoes a subsequent operation to create an extremely smooth surface. This surface is coated with a layer of material which is selected to maximize the reflectivity of the radiation. This reflective surface may be a single layer for wideband reflectivity, or a multilayer coating for optimizing the reflectivity in a narrower wavelength interval. The coated wire is built up with a reinforcing layer, typically by a plating operation. The initial wire is removed by either an etching procedure or mechanical force. Prior to removing the wire, the capillary is typically bonded to a support substrate.

Abstract: This invention is to ensure a high planarity of an underlying layer after a porous layer is removed. A substrate to be processed is dipped in an etchant. In the first step, pores in the porous Si layer are filled with the etchant by supplying an ultrasonic wave. In the second step, supply of the ultrasonic wave is stopped, and the pore walls are thinned by the etching function. In the third step, the ultrasonic wave is supplied again to break the porous layer at once.

Abstract: Fabrication methods are provided for microchips that control both the rate and time of release of multiple chemical substances and allow for the release of a wide variety of molecules in either a continuous or pulsatile manner. In all of the preferred embodiments, a material that is impermeable to the drugs or other molecules to be delivered and the surrounding fluids is used as the substrate. Reservoirs are etched into the substrate using either chemical (wet) etching or plasma (dry) etching techniques well known in the field of microfabrication. Hundreds to thousands of reservoirs can be fabricated on a single microchip using these techniques. A release system, which includes the molecules to be delivered, is inserted into the reservoirs by injection, inkjet printing, or spin coating methods. Exemplary release systems include polymers and polymeric matrices, non-polymeric matrices, and other excipients or diluents. The physical properties of the release system control the rate of release of the molecules.

Abstract: A flexible film interface includes a flexible film; flexible material attached to a portion of the flexible film; surface metallization on the flexible material, the flexible film having at least one via extending therethrough to the surface metallization; and a floating pad structure including floating pad metallization patterned over the flexible material and the surface metallization, a first portion of the floating pad metallization forming a central pad and a second portion of the floating pad metallization forming at least one extension from the central pad and extending into the at least one via.

Abstract: A method for fabricating a bump forming plate member by which bumps can be formed on an electronic component. A mask is formed on a surface of a crystalline plate, and the crystalline plate is subjected to anisotropic etching to form a plurality of grooves. The crystalline plate is also subjected to isotropic etching to deepen the grooves. The method can further includes additional anisotropic and isotropic etchings. Also, a method for fabricating a metallic bump forming plate member is disclosed. This method uses the above described crystalline plate having the grooves, and includes fabrication of a replica using the crystalline plate as an original, and fabrication of a metallic bump forming plate member using the replica as an original.

Abstract: A process is described for the manufacture of flexible tubular elements, particularly stents for the medical field, the process comprising the steps of:a) providing a hollow metal tube (or metal coated tube) with an open pattern of a chemical-etch-resistant coating layer;b) supporting the hollow metal tube with a coating thereon onto a chemical etch resistant support element;c) contacting the open pattern with a solution capable of etching the metal of the hollow metal tube so that said metal is etched away from physically exposed surfaces of the metal tube and openings in the metal tube corresponding to the open pattern of the coating layer are created in the metal tube element without etching the chemical etch resistant support element; andd) removing the metal tube from the chemical etch resistant support element.

Abstract: A method of forming adjacent ink and dilution solution nozzles in an orifice plate includes first providing an orifice plate having a thickness dimension. A first nozzle is then formed having a first orifice extending through the orifice plate at a first angular orientation that is generally normal to the thickness dimension. A second nozzle is then formed having a second orifice adjacent to the first orifice and at a second different angular orientation. One of the first and second nozzles is the ink nozzle and the other of the first and second nozzles is the dilution solution nozzle. The first and second nozzles are formed by laser light irradiation.

Abstract: Microfabricated filters utilizing a bulk substrate structure and a thin film structure and a method for constructing such filters. The pores of the filters are defined by spaces between the bulk substrate structure and the thin film structure and are of substantially uniform width, length and distribution. The width of the pores is defined by the thickness of a sacrificial layer and therefore may be smaller than the limit of resolution obtainable with photolithography. The filters provide enhanced mechanical strength, chemical inertness, biological compatibility, and throughput. The filters are constructed using relatively simple fabrication techniques. Also, microfabricated containment wells and capsules constructed with such filters for the immunological isolation of cell transplants and a method for constructing such containment wells and capsules.

Abstract: A method for fabricating a wafer-pair having at least one recess in one wafer and the recess formed into a chamber with the attaching of the other wafer which has a port plugged with a deposited layer on its external surface. The deposition of the layer may be performed in a very low pressure environment, thus assuring the same kind of environment in the sealed chamber. The chamber may enclose at least one device such as a thermoelectric sensor, bolometer, emitter or other kind of device. The wafer-pair typically will have numerous chambers, with devices, respectively, and may be divided into a multiplicity of chips.

Abstract: A method for forming a nozzle structure, as may be used in an ink-jet printer head, including first forming a layer of mold material on a substrate. The layer of mold material is shaped into a mold using photolithography and at least one etching step. A layer of nozzle material is then formed over the shaped mold material and the substrate. An aperture is formed through the nozzle material to the mold material, and the mold material is removed, leaving a chamber within the mold material; the chamber and aperture forming a nozzle structure.

Abstract: A process involving vapor etching of nuclear tracks in dielectric materials for creating high aspect ratio (i.e., length much greater than diameter), isolated cylindrical holes in dielectric materials that have been exposed to high-energy atomic particles. The process includes cleaning the surface of the tracked material and exposing the cleaned surface to a vapor of a suitable etchant. Independent control of the temperatures of the vapor and the tracked materials provide the means to vary separately the etch rates for the latent track region and the non-tracked material. As a rule, the tracked regions etch at a greater rate than the non-tracked regions. In addition, the vapor-etched holes can be enlarged and smoothed by subsequent dipping in a liquid etchant.

Abstract: A process for producing an ink jet recording head comprising a silicon substrate having an ink discharge pressure generating element for discharging ink, a discharge opening from which an ink is discharged, provided above the silicon substrate, an ink flow path communicating with the discharge opening, an ink feed opening through which the ink is fed to the ink flow path, and a support for supporting the silicon substrate, and being able to discharge a plurality of different inks, the process comprises the steps of subjecting the silicon substrate to anisotropic etching to form the ink feed opening for each ink and to simultaneously form a groove around the ink feed opening of the silicon substrate, and bonding the silicon substrate to the support in such a state that a protrusion provided on the support at its part corresponding to the groove of the silicon substrate is fitted to the groove.

Abstract: A diamond polycrystal body having metal films on its upper and lower surfaces is cut in the vertical direction using a laser to form a diamond polycrystal body piece having upper and lower surfaces and a cut surface connecting the upper and lower surfaces. The cut surface may be damaged and include graphite resulting from the laser cutting. To remove the damage and the graphite, the cut surface of the diamond polycrystal body piece is then plasma-treated. Thereby a prescribed degree of electrical insulation between the metallized upper and lower surfaces can be ensured.

Abstract: A microfabricated containment capsule has a bulk substrate delimiting a cavity with a boundary, a first portion of which constitutes an inner wall of a solid portion of the bulk substrate. The bulk substrate also provides at a second portion of the boundary a membrane joined to one side of the bulk substrate, the membrane having at least one porous area with controlled pores.

Abstract: Surface micromachining and bulk micromachining are employed for realizing a porous membrane with bulk support for a microparticle filter. The filter is manufactured by a process employing a thin film etch-stop, in which the bulk substrate is etched using a first etching process followed by etching of the etch stop and of material within pores of a filter layer using a second etching process. The filter is sufficiently sturdy to allow for easy handling. It may be used as a diffusion barrier and under high pressures. The disclosed fabrication method is simple, reliable, and integrated-circuit compatible, and thus amenable to mass production. Electronic circuitry may be integrated on the filter surface, as may be desired for several purposes, such as fluid characterization, filter self-cleaning, or charging of the filter surfaces. Methods are shown for the realization of biological containment capsules based on this microfilter.

Abstract: A thin film filter fabricated using surface micromachining. The width of the filter pores is determined by the thickness of a sacrificial thin-film layer. This dimension can be precisely controlled, and may be as small as about 50 angstroms. The pore length may also be determined by the thickness of thin film layers and can therefore be smaller than the limit of resolution obtainable with photolithography. The filters are suitable for use at high temperatures and with many harsh solvents.

Abstract: A microfabricated filter made up of two bonded substrate structures, each consisting of single crystalline silicon can optionally be formed into a capsule. The pores of the filter consist of one or more channels disposed between the two substrate structures. The width of the channels are defined by a thickness of a sacrificial layer formed on one of the substrate structures. The filter includes pores having a precisely controlled pore width which may be as small as 5 nanometers. The filter provides a relatively high mechanical strength relative to filters having polycrystalline silicon structures and also has a high throughput and can be modified to have high resistance to adsorption of particles.