Abstract: There is provided a technique of cleaning an interior of a supply part by performing a cycle a predetermined number of times, the cycle including: (a) supplying a first gas, which is one of a cleaning gas and an additive gas that reacts with the cleaning gas, from the supply part toward an interior of a process container in which a substrate has been processed by supplying a processing gas from the supply part to the substrate; and (b) supplying a second gas, which is the other one of the cleaning gas and the additive gas and is different from the first gas, from the supply part toward the interior of the process container in a state in which a part of the first gas remains in the supply part after supply of the first gas is stopped.

Abstract: A method for the dry removal of a material on a microelectronic workpiece is described. The method includes receiving a substrate having a working surface exposing a metal layer and having at least one other material exposed or underneath the metal layer; and differentially etching the metal layer relative to the other material by exposing the substrate to a controlled gas-phase environment containing an anhydrous halogen compound.

Abstract: The invention aims to provide a contactless method to create small conductive tracks on a substrate. To this end a method is provided for selective material deposition, comprising depositing a first material on a substrate; followed by solidifying the first material selectively in a first solidified pattern by one or more energy beams; and followed by propelling non-solidified material away from the substrate by a large area photonic exposure, controlled in timing, energy and intensity to leave the solidified first pattern of the first material.

Abstract: The invention provides a plasma processing method in which plasma etching is performed on a film to be etched by using a mask, the plasma processing method including: a deposition step of depositing a deposition film containing a boron element on the mask while a radio frequency power is supplied to a sample table on which a sample formed with the film to be etched is placed; and an etching step of etching the film to be etched by using plasma after the deposition step.

Abstract: A film formation device includes a target holder configured to hold a target for emitting sputtering particles in a processing space inside a processing chamber, a sputtering particle emitting part configured to emit the sputtering particles from the target, a sputtering particle shielding plate having a passage hole through which the emitted sputtering particles pass, a shielding member provided to shield the passage hole, a movement mechanism configured to move the shielding member in the horizontal direction, and a controller. The controller controls the shielding member, which has the placement portion on which a substrate is placed, to be moved in one direction of the horizontal direction, and controls the sputtering particles to be emitted from the target. The sputtering particles passed through the passage hole are deposited on the substrate.

Abstract: A plasma etching method of an embodiment includes performing etching on a silicon-containing film by using plasma of a fluorocarbon gas. The fluorocarbon gas used in the plasma etching method has a composition, regarding carbon and fluorine, represented by CxFy, wherein x and y are numbers satisfying x?7 and y?x, and includes a benzene ring structure composed of six carbon atoms.

Abstract: A sterilization process by means of heat treatment to preserve the ink of coleoid cephalopod molluscs includes the steps of homogenizing and first heat treating (1) the ink in a reactor for pasteurising treatment in which a temperature of at least 70° C. is attained for over 10 minutes; and cooling (2) the homogenized ink in a tank set to a temperature of below 30° C. and retaining the ink in the tank to lower its temperature. The process also includes the steps of continuing by filling, turning, blowing and marking (3) the expiry dates; and second heat treating (4) the ink in an autoclave in which a heat treatment is performed to achieve a sterilization temperature greater than or equal to 110° C. for a predetermined time based upon the quantity to be canned.

Abstract: A substrate transfer apparatus for transferring a substrate includes a plurality of vacuum transfer chambers, each having therein a substrate transfer mechanism for holding and transferring the substrate, and an intermediate chamber disposed between the vacuum transfer chambers adjacent to each other. When one of the vacuum transfer chambers adjacent to each other is set as a first vacuum transfer chamber and the other is set as a second vacuum transfer chamber, a first substrate loading/unloading port is disposed between the intermediate chamber and the first vacuum transfer chamber and a second substrate loading/unloading port is disposed between the intermediate chamber and the second vacuum transfer chamber. A gate valve is provided only for the second substrate loading/unloading port. Further, the first and the second substrate loading/unloading port have different height positions.

Abstract: A light deflector is provided including a mirror unit including a reflection plane, the mirror unit configured to rotate around a predetermined rotational axis, a pair of supporting beams configured to support the mirror unit in a rotatable manner, and drivers configured to drive the mirror unit to rotate, through the supporting beams. Each of the drivers has one end coupled to the supporting beams and another end coupled to a supporting unit formed to surround the mirror unit, and the supporting unit at least partially includes a thick portion and a thin portion different from each other in thickness.

Abstract: An etching gas mixture, a method of forming a pattern using the etching gas mixture, and a method of manufacturing an integrated circuit device using the etching gas mixture, the etching gas mixture including a C1-C3 perfluorinated alkyl hypofluorite; and a C1-C10 organosulfur compound that includes a C—S bond in the compound.

Abstract: An etching method of etching a silica-based residue containing a base component formed in an SiO2 film, includes selectively etching the silica-based residue by supplying an HF gas, an H2O gas or an alcohol gas to a target substrate having the SiO2 film, on which the silica-based residue is formed, and removing an etching residue caused by the selectively etching the silica-based residue, after the selectively etching the silica-based residue. The removing an etching residue includes a first process of supplying an H2O gas or an alcohol gas to the target substrate and a second process of heating the target substrate after the first process.

Abstract: A system is described for removing a dielectric gel, which has been layered atop the electrical components of a failed electrical system, without further damaging the electrical components of the failed electrical system. The system includes a raster component configured to project a laser for vaporizing a dielectric layer of an electric component into a plasma plume located above the dielectric layer. The system further includes a first vacuum nozzle positioned on a first side of the raster component and configured to extract a first portion of the plasma plume while the plasma plume is located above the dielectric layer, and a second vacuum nozzle positioned on a second side of the raster component and configured to extract a second portion of the plasma plume while the plasma plume is located above the dielectric layer.

Abstract: Provided is a method of etching a silicon-containing film made of at least one of silicon oxide and silicon nitride. The etching method includes: (i) preparing a workpiece having a silicon-containing film and a mask provided on the silicon-containing film in a chamber body of a plasma processing apparatus, in which an opening is formed in the mask; and (ii) etching the silicon-containing film, in which plasma is produced in the chamber body from processing gas containing fluorine, hydrogen, and iodine in order to etch the silicon-containing film, and a temperature of the workpiece is set to a temperature of 0° C. or less.

Abstract: After a discharge of a processing liquid is stopped, a position of a liquid surface within a nozzle can be observed. A substrate processing apparatus includes a substrate holding mechanism and the nozzle. The substrate holding mechanism is configured to hold a substrate. The nozzle is configured to supply the processing liquid to the substrate. The nozzle includes a pipe member and an observation window. The pipe member has a horizontal part and a downward part extended downwards from the horizontal part, and is configured to discharge the processing liquid from a tip end of the downward part. The observation window is provided at the horizontal part of the pipe member.

Abstract: A two-level tape frame rinse assembly is configured for grasping the substrate so as to create a gap between the substrate and a backside support plate that allows the backside of the wafer to be rinsed and spun dry after rinsing.

Abstract: According to one embodiment, a method of manufacturing a semiconductor device includes forming a first film on a substrate. The method further includes forming a second film on the first film. The method further includes simultaneously flowing a first gas with a second gas containing a metal element to form a first opening in the second film and forming a third film containing the metal element on a side surface of the first opening. The method further includes forming a second opening in the first film below the first opening using the second film as a mask.

Abstract: A system for reducing surface and embedded charge in a substrate includes a substrate support configured to support a substrate. A vacuum ultraviolet (VUV) assembly is arranged adjacent to the substrate and includes a housing and a VUV lamp that is connected to the housing and that generates and directs ultraviolet (UV) light at the substrate. A movement device is configured to move at least one of the VUV assembly and the substrate support during exposure of the substrate to the UV light to reduce surface and embedded charge in the substrate.

Abstract: A method is disclosed for monitoring and controlling a process of plasma-assisted surface modification of a layer formed on a substrate. The method includes flowing a surface modification gas into a plasma processing chamber of a plasma processing system, igniting a plasma in the plasma processing chamber to initiate a surface modification process for a layer formed on a substrate, and acquiring optical emission spectra from an optical emission spectroscopy system attached to the plasma processing chamber, during the surface modification process for the layer. For one embodiment, the method includes altering at least one parameter of the surface modification process based on the acquired optical emission spectra. For one embodiment, the acquired optical emission spectra can include an intensity of a spectral line, a slope of a spectral line, or both to enable endpoint control of the surface modification process. Additional methods and related systems are also disclosed.

Abstract: Various embodiments herein relate to methods, apparatus and systems for forming a recessed feature in a dielectric-containing stack on a semiconductor substrate. In many embodiments, a mask shrink layer is deposited on a patterned mask layer to thereby narrow the openings in the mask layer. The mask shrink layer may be deposited through a vapor deposition process including, but not limited to, atomic layer deposition or chemical vapor deposition. The mask shrink layer can result in narrower, more vertically uniform etched features. In some embodiments, etching is completed in a single etch step. In some other embodiments, the etching may be done in stages, cycled with a deposition step designed to deposit a protective sidewall coating on the partially etched features. Metal-containing films are particularly suitable as mask shrink films and protective sidewall coatings.

Abstract: Various embodiments herein relate to methods, apparatus and systems for forming a recessed feature in dielectric material on a semiconductor substrate. Separate etching and deposition operations are employed in a cyclic manner. Each etching operation partially etches the feature. Each deposition operation forms a protective coating on the sidewalls of the feature to prevent lateral etch of the dielectric material during the etching operations. The protective coating may be deposited using methods that result in formation of the protective coating along substantially the entire length of the sidewalls. The protective coating may be deposited using particular reactants and/or reaction mechanisms that result in substantially complete sidewall coating at relatively low temperatures without the use of plasma. In some cases the protective coating is deposited using molecular layer deposition techniques.

Abstract: A composition for primer layer coating of a water- and oil-repellent coating layer so as to enhance the durability of the water- and oil-repellent coating layer, comprises a mixture which comprises at least one of a silicon oxide (SiOx) and titanium (Ti) compound, an aluminum (Al) compound and a zirconium (Zr) compound. A preparation method may comprise: preparing a glass or polymer substrate; forming, on the substrate, a portion on which a fingerprint-resistant layer is to be deposited within the substrate by etching; depositing a primer layer consisting of the composition on the surface of the substrate including the portion where the water- and oil-repellent coating layer is deposited; forming the water- and oil-repellent coating layer on the deposited primer layer; and purging the substrate on which the water- and oil-repellent coating layer is formed. The method has excellent wear-resistance, salt water resistance, chemical resistance and cosmetics resistance.

Abstract: The present application relates to a block copolymer and uses thereof. The present application can provide a block copolymer—which exhibits an excellent self-assembling property and thus can be used effectively in a variety of applications—and uses thereof.

Abstract: A plasma processing equipment includes a vacuum processing chamber, an insulating material, a gas inlet, a high frequency induction antenna provided at an upper outside of the vacuum processing chamber, a magnetic field coil, a yoke for controlling distribution of a magnetic field in the vacuum processing chamber, a high frequency power supply for generating plasma and supplying a high frequency current to the antenna, and a power supply for supplying power to the magnetic field coil. The antenna is divided into n high frequency induction antenna elements are arranged in tandem on one circle so that a high frequency current delayed sequentially by ? (wavelength of high frequency power supply)/n flows clockwise through the antenna elements arranged in tandem via a delay unit, and a magnetic field is applied from the magnetic field coil to generate electron cyclotron resonance (ECR) phenomenon.

Abstract: Transition metal dry etch by atomic layer removal of oxide layers for device fabrication, and the resulting devices, are described. In an example, a method of etching a film includes reacting a surface layer of a transition metal species of a transition metal-containing film with a molecular oxidant species. The method also includes removing volatile fragments of the reacted molecular oxidant species to provide an oxidized surface layer of the transition metal species. The method also includes reacting the oxidized surface layer of the transition metal species with a molecular etchant. The method also includes removing the reacted oxidized surface layer of the transition metal species and the reacted molecular etchant by volatlilization.

Abstract: The present disclosure relates to an apparatus for heating and supporting a substrate in a processing chamber. A substrate support assembly includes a heated plate having a substrate supporting surface on a front side and a cantilever arm extending from a backside of the heated plate. The heated plate is configured to support and heat a substrate on the substrate supporting surface. The cantilever arm has a first end attached to the heated plate near a central axis of the heated plate, and a second end extending radially outwards from the central axis.

Abstract: According to aspects of the disclosed subject matter, a method of placing a solid state light source on a heat sink can include coating a surface of the heat sink with an anodized coating or an e-coating, for example. A portion of the coated surface can be treated via laser ablation for placing the solid state light source. Additionally, the laser ablation parameters can be adjusted to provide a predetermined roughness to the treated portion of the coated surface.

Abstract: The present invention provides a catalyst comprising a layer of metallic palladium implant¬ed with an inert gas ions, an electrochemical system containing thereof, a palladium-inert gas alloy stable in the normal conditions, use thereof and a fuel cell containing thereof.

Abstract: In order to remove from a substrate having a concavo-convex pattern formed on a surface of the substrate, a solid material with which a concave portion of the concavo-convex pattern is filled and which is formed by evaporating a solvent in a sublimable substance solution containing a sublimable substance that sublimates at a temperature equal to or higher than a first temperature, and an impurity that evaporates at a temperature equal to or higher than a second temperature that is higher than the first temperature, the prevent invention provides a substrate processing apparatus and a substrate processing method which heat the substrate to a temperature equal to or higher than the second temperature.

Abstract: At least one method, apparatus and system disclosed involves providing an integrated circuit having metal feature flyover over an middle-of-line (MOL) feature. A first location for a non-contact intersection region between a first middle of line (MOL) interconnect feature and a metal feature in a functional cell is determined. A dielectric feature is formed over the first MOL interconnect feature at the first location. The metal feature is formed over the dielectric layer, the dielectric layer providing a predetermined amount of voltage isolation between the first MOL interconnect feature and the metal feature.

Abstract: The present disclosure provides advantageous composite films/coatings, and improved methods for fabricating such composite films/coatings. More particularly, the present disclosure provides improved methods for fabricating composite films by trapping at least a portion of a layered material (e.g., hexagonal boron nitride sheets/layers) at an interface of a phase separated system and then introducing the layered material to a polymer film. The present disclosure provides for the use of boron nitride layers to increase the properties (e.g., dielectric constant and breakdown voltage) of polymer films. The exemplary films can be produced by an advantageous climbing technique. Exemplary boron nitride films are composed of overlapping boron nitride sheets with a total thickness of about one nanometer, with the film then transferred onto a polymer film, thereby resulting in significant increases in both dielectric and breakdown properties of the polymer film.

Abstract: Embodiments of the present disclosure generally provide improved methods for processing substrates with improved process stability, increased mean wafers between clean, and/or improved within wafer uniformity. One embodiment provides a method for seasoning one or more chamber components in a process chamber. The method includes placing a dummy substrate in the process chamber, flowing a processing gas mixture to the process chamber to react with the dummy substrate and generate a byproduct on the dummy substrate, and annealing the dummy substrate to sublimate the byproduct while at least one purge conduit of the process chamber is closed.

Abstract: A method is described for vapor phase etching of oxide material including at least one of hafnia (HfO2) and zirconia (ZrO2), in the absence of plasma exposure of the oxide material. The method involves contacting the oxide material with an etching medium including at least one of phosphorus chloride and tungsten chloride under conditions producing a removable fluid reaction product, and removing the removable fluid reaction product. The etching process may be controllably carried out by use of pressure swings, temperature swings, and/or modulation of partial pressure of Hf or Zr chloride in the reaction, e.g., to achieve precision etch removal in the manufacture of semiconductor devices such as 3D NAND, sub-20 nm DRAMs, and finFETs.

Abstract: Provided is a technique capable of obtaining a satisfactory yield for a semiconductor device with an air gap. The technique includes a method of manufacturing a semiconductor device, including: (a) receiving a thickness information of a wiring layer formed on a substrate including: a first interlayer insulation film; and the wiring layer disposed on the first interlayer insulation film, the wiring layer including: copper-containing films used as wiring; and an inter-wiring insulation film having trenches filled with the copper-containing films and insulating the copper-containing films; (b) placing the substrate on a substrate support installed in a process chamber; and (c) etching the wiring layer using an etching gas based on an etching control value corresponding to the thickness information of the wiring layer.

Abstract: At least one method, apparatus and system disclosed involves providing an integrated circuit having metal feature flyover over an middle-of-line (MOL) feature. A first location for a non-contact intersection region between a first middle of line (MOL) interconnect feature and a metal feature in a functional cell is determined. A dielectric feature is formed over the first MOL interconnect feature at the first location. The metal feature is formed over the dielectric layer, the dielectric layer providing a predetermined amount of voltage isolation between the first MOL interconnect feature and the metal feature.

Abstract: A method of manufacturing a semiconductor device including a wafer using a plasma etching device which includes a chamber, a chuck provided in the chamber to dispose a wafer to be processed thereon, a focus ring disposed at a peripheral edge portion of the chuck, and a gas supplying mechanism configured to supply various types of gases depending a radial position of the wafer. The method includes: placing a wafer formed with an organic film on the chuck; introducing an etching gas which etches the organic film on the wafer from the process gas supplying mechanism to a central portion of the wafer; introducing an etching inhibiting factor gas having a property of reacting with the etching gas to the peripheral edge portion of the wafer from the gas supplying mechanism; and performing plasma etching on the wafer using the etching gas.

Abstract: A microconduit network structure and methods for making the same. One aspect of the invention relates to a microconduit network structure, including: a solid or semi-solid matrix having at least one interconnected web of filaments formed within the matrix; and wherein at least one interconnected web of filaments having diameters of about 10 nm to about 1 mm.

Abstract: A focused ion beam apparatus is equipped with a gas field ion source that can produce a focused ion beam for a long period of time by stably and continuously emitting ions from the gas field ion source having high luminance, along an optical axis of an ion-optical system for a long period of time. The gas field ion source has an emitter for emitting ions, the emitter having a sharpened end part made of iridium fixed to a cylinder-shaped base part made of dissimilar wire.

Abstract: A thermal bridge connecting first and second processing zones and a method for transferring a work piece from a first to a second processing zone by way of the thermal bridge are disclosed. A work piece, transportable from the first to the second processing zone on or above the thermal bridge, is maintained at a temperature between the temperatures of the processing zones. The thermal bridge member features a thermally conductive transport member for the work piece supported over an infrared transmissive member that is insulative to heat conduction and convection. The bridge insulative member extends between the first and second processing zones or between reactors. An infrared radiation beam source emits infrared radiation which passes through the bridge insulative member to the transport member, heating the member. In an alternate embodiment, the transport member may be heated directly. A liner member may be mounted above the bridge member to retain heat.

Abstract: Methods are described herein for selectively etching titanium nitride relative to dielectric films, which may include, for example, alternative metals and metal oxides lacking in titanium and/or silicon-containing films (e.g. silicon oxide, silicon carbon nitride and low-K dielectric films). The methods include a remote plasma etch formed from a chlorine-containing precursor. Plasma effluents from the remote plasma are flowed into a substrate processing region where the plasma effluents react with the titanium nitride. The plasma effluents react with exposed surfaces and selectively remove titanium nitride while very slowly removing the other exposed materials. The substrate processing region may also contain a plasma to facilitate breaking through any titanium oxide layer present on the titanium nitride. The plasma in the substrate processing region may be gently biased relative to the substrate to enhance removal rate of the titanium oxide layer.

Abstract: An etching method for etching an object to be processed in a processing chamber including a first electrode and a second electrode disposed facing the first electrode and configured to receive the object to be processed thereon is provided that includes steps of intermittently supplying first high frequency power to either the first electrode or the second electrode while supplying second high frequency power lower than the first high frequency power to the second electrode, supplying a process gas containing hydrogen bromide HBr and oxygen O2 into the processing chamber, and etching a poly silicon film deposited on the object to be processed into a mask pattern of a silicon-containing oxide film patterned by a spacer double patterning method by plasma generated from the process gas.

Abstract: A semiconductor device manufacturing method for etching a multilayer film using a mask is provided. The method includes (a) supplying a first gas containing hydrogen, hydrogen bromide, nitrogen trifluoride and at least one of hydrocarbon, fluorocarbon and fluorohydrocarbon into the processing chamber and exciting the first gas to etch the multilayer film from a top surface of the multilayer film to a predetermined position in a stacked direction of the multilayer film; and (b) supplying a second gas that does not substantially contain hydrogen bromide and contains hydrogen and nitrogen trifluoride and at least one of Thydrocarbon, fluorocarbon and fluorohydrocarbon into the processing chamber and exciting the second gas to etch the multilayer film from the predetermined position of the multilayer film to a top surface of the etching stop layer.

Abstract: A method for manufacturing a silicon carbide semiconductor substrate is provided to offer a silicon carbide semiconductor substrate having a highly flat surface at low cost. The method includes: a step of preparing a silicon carbide substrate as a seed substrate; a step of performing vapor phase etching onto a main surface of the silicon carbide substrate; and a step of epitaxially growing silicon carbide on the main surface. A carbon-atom containing gas is supplied to silicon carbide substrate from a point of time in the step of performing the vapor phase etching.

Abstract: Cable foil tape having random or pseudo-random patterns or long pattern lengths of discontinuous metallic shapes and a method for manufacturing such patterned foil tape are provided. In some embodiments, a laser ablation system is used to selectively remove regions or paths in a metallic layer of a foil tape to produce random distributions of randomized shapes, or pseudo-random patterns or long pattern lengths of discontinuous shapes in the metal layer. In some embodiments, the foil tape is double-sided, having a metallic layer on each side of the foil tape, and the laser ablation system is capable of ablating nonconductive pathways into the metallic layer on both sides of the foil tape.

Abstract: Verticality of a space formed in the multilayered film can be improved while suppressing an opening of a mask from being clogged. The multilayered film includes a first film and a second film that have different permittivities and are alternately stacked on top of each other. An etching method of etching the multilayered film includes preparing, within a processing vessel of a plasma processing apparatus, a processing target object having the multilayered film and a mask provided on the multilayered film; and etching the multilayered film by exciting a processing gas containing a hydrogen gas, a hydrofluorocarbon gas, a fluorine-containing gas, a hydrocarbon gas, a boron trichloride gas and a nitrogen gas within the processing vessel.

Abstract: An apparatus and methods utilized a DC or AC power to supply through a conductive substrate support pedestal to a conductive photomask substrate during a photomask substrate manufacturing process for EUV or other advanced lithography applications are provided. In one embodiment, an apparatus for processing a photomask includes a substrate support pedestal configured to receive a conductive photomask, wherein the conductive photomask is fabricated from a dielectric material substrate with a conductive coating, and at least a conductive path formed in the substrate support pedestal in contact with the photomask substrate configured to be conductive.

Abstract: It is possible to efficiently remove deposited materials such as a conductive film or insulting film adhered to parts such as the inner wall of a processing chamber and a substrate supporting tool disposed in the processing chamber. There is provided a method of manufacturing a semiconductor device. The method comprises: loading a substrate into a processing chamber; forming a conductive film or an insulating film on the substrate by supplying a plurality of source gases into the processing chamber; unloading the substrate from the processing chamber; and modifying a conductive film or an insulating film adhered to the processing chamber by supplying a modifying gas into the processing chamber. After performing a cycle of the loading, the forming, the unloading, and the modifying processes a plurality of times, the modified conductive film or the modified insulating film adhered to the processing chamber is removed from the processing chamber by supplying a cleaning gas into the processing chamber.

Abstract: One embodiment of the deposit removal method includes: preparing a substrate having a pattern on which a deposit is deposited, the pattern being formed by etching; exposing the substrate to a first atmosphere containing hydrogen fluoride gas; exposing the substrate to oxygen plasma while heating after the step of exposing the substrate to the first atmosphere; and exposing the substrate to a second atmosphere containing hydrogen fluoride gas to remove the deposit on the substrate after the step of exposing the substrate to the oxygen plasma.

Abstract: A microconduit network structure and methods for making the same. One aspect of the invention relates to a microconduit network structure, including: a solid or semi-solid matrix having at least one interconnected web of filaments formed within the matrix; and wherein at least one interconnected web of filaments having diameters of about 10 nm to about 1 mm.

Abstract: A deposit removal method for removing deposits deposited on the surface of a pattern formed on a substrate by etching, includes an oxygen plasma treatment process for exposing the substrate to oxygen plasma while heating the substrate and a cycle treatment process for, after the oxygen plasma treatment process, repeating multiple cycles of a first period and a second period. In the first period, the substrate is exposed to a mixture of hydrogen fluoride gas and alcohol gas inside a processing chamber and the partial pressure of the alcohol gas is set to the first partial pressure. In the second period, the partial pressure of the alcohol gas is set to the second partial pressure lower than the first partial pressure by exhausting the inside of the processing chamber.

Abstract: A method for sharpening a nanotip involving a laser-enhanced chemical etching is provided. The method includes immersing a nanotip in an etchant solution. The nanotip includes a base and an apex, the apex having a diameter smaller than a diameter of the base. The method also includes irradiating the nanotip with laser fluence to establish a temperature gradient in the nanotip along a direction from the apex to the base of the nanotip such that the apex and base are etched at different rates.