Showing papers on "Focused ion beam published in 2003"
IBM1
251 citations
TL;DR: In this article, the effects of the ion beam-solid interaction determining the formation of small structures by ion-beam sputtering and chemically assisted material deposition and etching are investigated.
Abstract: Focused ion beams with diameters of 8 to 50 nm are used for material processing in the nanoscale regime. In this paper, effects of the ion beam–solid interaction determining the formation of small structures by ion-beam sputtering and chemically assisted material deposition and etching are investigated. In the case of decreasing feature size, angle-dependent sputtering, a non-constant sputter rate, and scattered ions play an important role. The impact on side-wall angle, aspect ratio, and shape of the bottom of the etched structures is discussed. In beam tail regions, these effects will be especially pronounced, leading to material swelling instead of material removal. Ion beam assisted etching and deposition will face additional effects. For small structures, gas depletion becomes a significant drawback. The impact on gas depletion and the competition with sputtering are discussed.
145 citations
TL;DR: In this article, the focusing effects of fine glass capillary optics for MeV He ion beams were investigated and it was shown that the majority of incident ions are lost by the dechanneling, or large-angle scattering process, however, a part of them, actually about 1% more or less, is emitted through the outlet without significant energy loss.
Abstract: We present evidence of the focusing effects of fine glass capillary optics for MeV He ion beams. The glass capillary optics are formed by a puller as to have inlet diameters of about 1 mm and outlet diameters of submicrons. The total length of the optics is about 50 mm. Impingent MeV ions to such optics are reflected by the inner wall several times, in a very similar process to the so-called surface channeling. The majority of incident ions are lost by the dechanneling, or large-angle scattering process, however, a part of them, actually about 1% more or less, is emitted through the outlet without significant energy loss. Compared with the conventional micro-ion beam facilities, the present method is certainly simple and lowcost, thus providing an easy method of submicron Rutherford backscattering spectrometry or particle induced x-ray emission analyses. In addition, if the ion species are extended to heavier elements, the present method provides versatile maskless ion implantation techniques.
119 citations
TL;DR: In this paper, the material composition and crystal structure of diamond-like-carbon free-space-wiring were studied by transmission-electron microscopy and energy-dispersive x-ray spectroscopy.
Abstract: Focused-ion-beam chemical vapor deposition (FIB-CVD) is an excellent technology for forming three-dimensional nanostructures. Various diamond-like-carbon (DLC) free-space-wirings have been demonstrated by FIB-CVD using a computer-controlled pattern generator, which is a commercially available pattern generator for electron-beam (EB) lithography. The material composition and crystal structure of DLC free-space-wiring were studied by transmission-electron microscopy and energy-dispersive x-ray spectroscopy. As a result, it became clear that DLC free-space-wiring is amorphous carbon containing a Ga core in the wire. Furthermore, the electrical resistivity measurement of DLC free-space-wiring was carried out by two terminal electrodes. Au electrodes were fabricated by EB lithography and a lift-off process. The electrical resistivity was about 100 Ω cm at room temperature.
116 citations
01 Jan 2003-Precision Engineering-journal of The International Societies for Precision Engineering and Nanotechnology
TL;DR: Focused ion beam (FIB) sputtering is used to shape a variety of cutting tools with dimensions in the 15-100-μm range and cutting edge radii of curvature of 40-nm.
Abstract: Focused ion beam (FIB) sputtering is used to shape a variety of cutting tools with dimensions in the 15–100 μm range and cutting edge radii of curvature of 40 nm. The shape of each microtool is controlled to a pre-specified geometry that includes rake and relief features. We demonstrate tools having rectangular, triangular, and other complex-shaped face designs. A double-triangle tip on one tool is unique and demonstrates the versatility of the fabrication process. The FIB technique allows observation of the tool during fabrication, and, thus, reproducible features are generated with sub-micron precision. Tools are made from tungsten carbide, high-speed tool steel, and single crystal diamond. Application of FIB-shaped tools in ultra-precision microgrooving tests shows that the cross-section of a machined groove is an excellent replication of the microtool face. Microgrooves on 40–150 μm pitch are cut into 3 mm diameter polymer rods, for groove arc lengths greater than 12 cm. The surface finish of machined features is also reported; groove roughness (Ra) is typically less than 0.2 μm. Ultra-precision machining of cylindrical substrates is extended to make bound metal microcoils having feature sizes of 20–40 μm.
116 citations
TL;DR: In this article, a nanostencil was used for flexible and rapid surface patterning technique beyond lithography based on high-resolution shadow mask method, which can be used to create micro/nanoscale patterns on arbitrary substrates including mechanically fragile or chemically active surfaces.
106 citations
TL;DR: In this article, the authors used the focused ion beam (FIB) technique to obtain electron-transparent slices from specific parts of the wider veins and lifted out for TEM study.
Abstract: Transmission electron microscope samples were prepared of ALH 78045 and ALH 88045, two clay-and phyllosilicate-bearing Antarctic meteorites, using argon ion milling and focused ion beam (FIB) techniques. ALH 78045 contains clay- and phyllosilicate-filled veins that have formed by terrestrial weathering of olivine, orthopyroxene and metal. Very narrow (∼10 nm) intragranular clay-filled veins could be observed in the TEM samples prepared by argon ion milling, whereas differential thinning and lack of precision in the location of the electron-transparent areas hindered the study of wider (5 — 15 μm) phyllosilicate-filled intergranular veins. Using the FIB instrument, electron-transparent slices were cut from specific parts of the wider veins and lifted out for TEM study. Results show that these veins are occluded by cronstedtite, a mixed-valence Fe-rich phyllosilicate. This discovery shows that silicates can be both dissolved and precipitated during terrestrial weathering within the Antarctic ice. ALH 88045 is one of a small number of known CM1 carbonaceous chondrites. This meteorite is largely composed of flattened ellipsoidal aggregates of serpentine-group phyllosilicates. To determine the mineralogy and texture of phyllosilicates within specific aggregates, TEM samples were prepared by trenching into the cut edge of a sample using the FIB instrument. Results show that Mg-rich aggregates are composed of lath-shaped serpentine crystals with a ∼0.73 nm basal spacing, which is typical of the products of low temperature aqueous alteration within asteroidal parent bodies. Results of this work demonstrate that the FIB has enormous potential in a number of areas of Earth and planetary science.
102 citations
TL;DR: The fundamental ion/solid interactions that govern the FIB milling process are examined and discussed with respect to the preparation of electron transparent membranes and the roles of incident ion attack angle, beam current, trench geometry, raster pattern, and target-material-dependent removal rates are considered.
Abstract: The focused ion beam (FIB) tool has been successfully used as both a stand alone analytical instrument and a means to prepare specimens for subsequent analysis by SEM, TEM, SIMS, XPS, and AUGER. In this work, special emphasis is given to TEM specimen preparation by the FIB lift-out technique. The fundamental ion/solid interactions that govern the FIB milling process are examined and discussed with respect to the preparation of electron transparent membranes. TRIM, a Monte Carlo simulation code, is used to physically model variables that influence FIB sputtering behavior. The results of such computer generated models are compared with empirical observations in a number of materials processed with an FEI 611 FIB workstation. The roles of incident ion attack angle, beam current, trench geometry, raster pattern, and target-material-dependent removal rates are considered. These interrelationships are used to explain observed phenomena and predict expected milling behaviors, thus increasing the potential for the FIB to be used more efficiently with reproducible results.
100 citations
TL;DR: In this paper, the authors used the focused ion beam (FIB) technique to detect the presence of small Pb-rich domains where large variations in EMP ages occur and suggest that radiogenic Pb was partially reincorporated in monazite during the recrystallization at 790 Ma.
Abstract: Electron-microprobe (EMP) U-Th-Pb dating on polyphase and discordant monazites from polymetamorphic granulites of the Andriamena unit (north-central Madagascar) reveals inconsistent chemical ages. To explain these drastic variations, transmission electron microscopy (TEM) foils were prepared directly from thin sections by using the focused ion beam technique. The most important result of the TEM study is the demonstration of the presence of small (~50 nm) Pb-rich domains where large variations in EMP ages occur. We suggest that radiogenic Pb was partially reincorporated in monazite during the recrystallization at 790 Ma. Because the excited volume of EMP is ~4 µm3, U-Th-Pb dating yielded various apparent older ages without geological significance. In addition, TEM analysis of the foils revealed the presence of an ~150-nm-wide amorphous zone along the grain boundary of monazite and its host quartz. This Fe-Si-Al–rich phase may have formed as a result of fluid activity at 500 Ma, and the phase's amorphous state may be due to the irradiation from U and Th decay in the monazite. This demonstrates for the first time the enormous potential of the TEM investigations on site-specific specimens prepared with the focused ion beam technique for the interpretation of geochronological data.
100 citations
TL;DR: In this paper, a new method for the in situ measurement of the residual stresses, σR, in thin films, thickness h, is described based on the combined capability of the focused ion beam (FIB) imaging system and of high-resolution strain mapping software (vic-2d).
96 citations
TL;DR: In this paper, the effects of H2O vapor introduced during focused ion beam (FIB) milling of diamond(100) are examined, and the yield, surface morphology, and microstructural damage that results from FIB sputtering and h2O-assisted FIB milling processes are determined.
Abstract: The effects of H2O vapor introduced during focused ion beam (FIB) milling of diamond(100) are examined. In particular, we determine the yield, surface morphology, and microstructural damage that results from FIB sputtering and H2O-assisted FIB milling processes. Experiments involving 20 keV Ga+ bombardment to doses ∼1018 ions/cm2 are conducted at a number of fixed ion incidence angles, θ. For each θ selected, H2O-assisted ion milling shows an increased material removal rate compared with FIB sputtering (no gas assist). The amount by which the yield is enhanced depends on the angle of incidence with the largest difference occurring at θ=75°. Experiments that vary pixel dwell time from 3 μs to 20 ms while maintaining a fixed H2O gas pressure demonstrate the additional effect of beam scan rate on yield for gas-assisted processes. Different surface morphologies develop during ion bombardment depending on the angle of ion incidence and the presence/absence of H2O. In general, a single mode of ripples having a wave vector aligned with the projection of the ion beam vector forms for θ as high as 70°. H2O affects this morphology by lowering the ripple onset angle and decreasing the ripple wavelength. At high angles of incidence (θ>70°) a step/terrace morphology is observed. H2O-assisted milling at θ>70° results in a smoother stepped surface compared with FIB sputtering. Transmission electron microscopy shows that the amorphized thickness is reduced by 20% when using H2O-assisted FIB milling.
TL;DR: In this article, the electrical properties of Pt nano-interconnects, formed on SiO2 substrates by focused-ion-beam deposition, were studied, and they were found to have a small residual resistivity ratio, and a Debye temperature that differs significantly from that of pure Pt, indicative of the disordered nature of the nanowires.
Abstract: We study the electrical properties of Pt nanointerconnects, formed on SiO2 substrates by focused-ion-beam deposition. Studies of their temperature-dependent resistivity reveal a small residual-resistivity ratio, and a Debye temperature that differs significantly from that of pure Pt, indicative of the disordered nature of the nanowires. Their magnetoresistance shows evidence for weak antilocalization at temperatures below 10 K, with a phase-breaking length of ∼100 nm, and a temperature dependence suggestive of quasi-one-dimensional interference.
TL;DR: In this article, single-walled carbon nanotubes have been grown on a variety of substrates by chemical vapor deposition using low-coverage vacuum-deposited iron as a catalyst.
Abstract: Single-walled carbon nanotubes have been grown on a variety of substrates by chemical vapor deposition using low-coverage vacuum-deposited iron as a catalyst. Ordered arrays of suspended nanotubes ranging from submicron to several micron lengths have been obtained on Si, SiO 2 , Al 2 O 3 , and Si 3 N 4 substrates that were patterned on hundred nanometer length scales with a focused ion beam machine. Electric fields applied during nanotube growth allow the control of growth direction. Nanotube circuits have been constructed directly on contacting metal electrodes of Pt/Cr patterned with catalysts. Patterning with solid iron catalyst is compatible with modern semiconductor fabrication strategies and may contribute to the integration of nanotubes in complex device architectures.
TL;DR: In this paper, a hexagonal-closed-packed pattern is created by focused ion beam (FIB) exposure of the polymethylmethacrylate (PMMA) resist and transferred onto the aluminum surface by phosphoric acid etching.
Abstract: Long-range ordered arrays of anodic alumina nanochannels are grown by anodizing an aluminum covered with a patterned layer of polymethylmethacrylate (PMMA) resist. The two-dimensional hexagonal-closed-packed pattern is created by focused ion beam (FIB) exposure of the PMMA and transferred onto the aluminum surface by phosphoric acid etching. The required exposure time per channel is only ∼20 μs, more than two orders of magnitude reduction in comparison with the previous method employing FIB direct sputtering of the aluminum surface.
TL;DR: In this article, the impact of shrinking feature sizes on the sputter efficiency of focused ion beams on crystalline silicon was investigated, and the main competitive mechanisms determining the complex response of silicon were demonstrated.
Abstract: We have investigated the impact of shrinking feature sizes on the sputter efficiency of focused ion beams on crystalline silicon. On the basis of this analysis, we have demonstrated the main competitive mechanisms determining the complex response of silicon. Low-dose irradiation with a 50-keV Ga+ beam in the range from 1013 ions/cm2 to 1015 ions/cm2 produced pronounced swelling of the silicon due to amorphization. Higher doses led to material removal with an efficiency of about 2.5 atoms/ion. A sputter yield promoting the self-focusing effect combined with the sputter rate increase at oblique angles, and an opposing dose-deficiency effect, determined the complex characteristics of nanoscale trench milling. Shrinking critical dimensions led to higher sputter yields, attributable to self-focusing effects of incident ions becoming dominant at aspect ratios in the region of unity. At aspect ratios beyond unity, re-deposition was the dominant effect.
TL;DR: In this paper, the nucleation sites of nanoscale, self-assembled Ge islands on Si(001) can be controlled by patterning the Si surface in situ with a focused ion beam.
Abstract: We demonstrate that the nucleation sites of nanoscale, self-assembled Ge islands on Si(001) can be controlled by patterning the Si surface in situ with a focused ion beam. At low doses of 6000 Ga+ ions per <100 nm spot, the selective growth is achieved without modifying the initial surface topography. At larger doses, topographic effects produced by sputtering and redeposition control the selective nucleation sites. Islands grown on irradiated spots are smaller with higher aspect ratio than islands grown on clean Si(001), suggesting a strong surfactant effect of Ga.
TL;DR: In this article, the application of focused ion beam techniques to prepare cross-sections of wear tracks is presented, which reveals the formation of two subsurface zones, each with its own characteristic features.
TL;DR: In this paper, the role of dynamic annealing (defect-annihilation) is discussed with an emphasis on the fluence-dependent defect structure and point-defect clusters are identified as major component in irradiated chemical-vapor-deposited GaN nanowires.
Abstract: Ga+ ion implantation of chemical-vapor-deposited GaN nanowires (NWs) is studied using a 50-keV Ga+ focused ion beam The role of dynamic annealing (defect-annihilation) is discussed with an emphasis on the fluence-dependent defect structure Unlike heavy-ion-irradiated epitaxial GaN film, large-scale amorphization is suppressed until a very high fluence of 2×1016 ions cm−2 In contrast to extended-defects as reported for heavy-ion-irradiated epitaxial GaN film, point-defect clusters are identified as major component in irradiated NWs Enhanced dynamic annealing induced by high diffusivity of mobile point-defects in the confined geometry of NWs is identified as the probable reason for observed differences
TL;DR: In this paper, a focused ion beam nanofabrication technique was investigated as a high-resolution patterning method suitable for nanocontact imprinting, and different ion beam currents, milling times, and dwell times were exploited to optimize focused ionbeam milling conditions.
Abstract: We investigated a focused ion beam nanofabrication technique as a high-resolution patterning method suitable for nanocontact imprinting. Different ion beam currents, milling times, and dwell times are exploited to optimize focused ion beam milling conditions. Single-pixel lines are milled on a silicon master and replicated on polydimethylsiloxane through replica moulding. The profile of the grooves (the depth-to-width aspect ratio) was found to be depth dependent regardless of the beam current and dwell time. The depth of the line cuts was strongly dependent upon beam current and dwell time at a given dose. This technique holds great promise for mass production of nanostructures due to its simplicity and high reproducibility.
Patent•
06 Aug 2003TL;DR: In this article, a co-axial focused ion beam and an electron beam were used for accurate processing with the FIB using images formed by the electron beam, and the landing energy of the electrons can be varied without changing the working distance.
Abstract: A system including co-axial focused ion beam and an electron beam allows for accurate processing with the FIB using images formed by the electron beam. In one embodiment, a deflector deflects the electron beam onto the axis of the ion beam and deflects secondary particles collected through the final lens toward a detector. In one embodiment, a positively biased final electrostatic lens focuses both beams using the same voltage to allow simultaneous or alternating FIB and SEM operation. In one embodiment, the landing energy of the electrons can be varied without changing the working distance.
TL;DR: TEM and 3D crack analysis by focused ion beam (FIB) cross sectioning have been used to quantify the subsurface damage beneath scratches made by a 120° cone indenter loaded to 1 N in monolithic polycrystalline alumina and alumina/5vol.%SiC nanocomposites as mentioned in this paper.
Patent•
13 Jun 2003
TL;DR: In this article, a self-supporting thin-film layer is formed through thin film deposition techniques, which results in a self supporting thin film layer that can have a precisely defined channel bored there through.
Abstract: A solid state device is formed through thin film deposition techniques which results in a self-supporting thin film layer that can have a precisely defined channel bored therethrough The device is useful in the chacterization of polymer molecules by measuring changes in various electrical characteristics as molecules pass through the channel To form the device, a thin film layer having various patterns of electrically conductive leads are formed on a silicon substrate Using standard lithography techniques, a relatively large or micro-scale aperture is bored through the silicon substrate which in turn exposes a portion of the thin film layer This process does not affect the thin film Subsequently, a high precision material removal process is used (such as a focused ion beam) to bore a precise nano-scale aperture through the thin film layer that coincides with the removed section of the silicon substrate
TL;DR: In this article, the authors used focused ion beam-induced chemical vapor deposition (FIB-CVD) to grow 3D tungsten structures with a milling process by using FIB treatment subsequent to growth.
Abstract: Sidewall morphology on three-dimensional (3D) tungsten structures grown with focused ion beam-induced chemical vapor deposition (FIB-CVD) using tungsten hexacarbonyl [W(CO)6] was improved with a milling process by using FIB treatment subsequent to growth. As a result, Young’s modulus was measured at 300 GPa at maximum and density was measured at 13.0×103 kg/m3. Young’s modulus increased 35% after heat treatment at 600 °C in a vacuum while density did not change. Transmission electron microscopy revealed crystallization of tungsten trioxide after the heat treatment.
TL;DR: In this article, a focused ion beam of Ga ions is used to sample electrontransparent foils, which crossed Wm-sized diamonds included in host minerals such as zircon and garnet from quartzofeldspathic rocks of the Saxonian Erzgebirge, Germany.
TL;DR: In this article, a 3D pattern-generating system for free-designed 3D structures using focused ion-beam chemical-vapor deposition is presented. But the 3D structure is fabricated by scanning 30 keV Ga+ ion-beam-assisted deposition in a 1×10−4 Pa phenanthrene atmosphere.
Abstract: We studied the fabrication of free-designed three-dimensional (3D) structures by using focused-ion-beam chemical-vapor deposition. The 3D structures are fabricated by scanning 30 keV Ga+ ion-beam-assisted deposition in a 1×10−4 Pa phenanthrene atmosphere. The scanning pattern and blanking signal of the ion beam are generated by a 3D computer-aided-designed model using a computer pattern-generating system. This 3D pattern-generating system is able to fabricate overhang and hollow structures by setting suitable parameters (for example, plot pitch, dwell time, time interval of irradiations, and priorities of scanning). In this article, we demonstrate the performance of a 3D pattern-generating system by fabricating a 1:100 000 000 scale model of the Enterprise spaceship, a microring, a moth’s eyelike structure, and a morpho butterflylike structure with 200 nm spacing.
01 May 2003-Nuclear Instruments & Methods in Physics Research Section B-beam Interactions With Materials and Atoms
TL;DR: In this paper, the size distributions of large current Ar cluster ion beam were measured using time-of-flight method, and the distributions proved that the neutral beams include clusters with the size up to 160,000 atoms and that the distributions can be controlled by the source gas pressure and ionization condition.
Abstract: High ion dose is needed to realize the nano-level smoothing and etching of hard materials with increasing the productivity of processing using cluster ion beam. In order to achieve large current cluster ion beam, the cluster generation, ionization and ion transportation were studied. The intensity of neutral cluster beam increased with source gas pressure. The efficient ionization and extraction were realized by structural improvement of the ionizer. As a result, when the gas pressure was 15,000 Torr and the electron emission current is 300 mA, the beam current reached 500 μA. The size distributions of large current Ar cluster ion beam were measured using time-of-flight method. The distributions prove that the neutral beams include clusters with the size up to 160,000 atoms and that the distributions can be controlled by the source gas pressure and ionization condition.
TL;DR: A material may be removed from the top electrode of a film bulk acoustic resonator to alter the mass loading effect and to adjust the frequency of one film bulk resonator on a wafer relative to other resonators on the same wafer as mentioned in this paper.
Abstract: A material may be removed from the top electrode of a film bulk acoustic resonator to alter the mass loading effect and to adjust the frequency of one film bulk acoustic resonator on a wafer relative to other resonators on the same wafer. Similarly, the piezoelectric layer or the bottom electrode may be selectively milled with a focused ion beam to trim the resonator.
TL;DR: A focused ion beam (FIB) microscope has been used to fabricate junctions with dimensions in the range 100-5000 nm by three-dimensional etching as mentioned in this paper, and applied this process to a variety of structures, including current-perpendicular-to-plane giant-magnetoresistive multilayer devices, where the metal is Mo, Co, or a CuxNi1−x alloy, and GaN light-emitting diodes.
Abstract: A focused ion beam (FIB) microscope has been used to fabricate junctions with dimensions in the range 100–5000 nm by three-dimensional etching. We have applied this process to a variety of structures, including current-perpendicular-to-plane giant-magnetoresistive multilayer devices, superconductor–metal–superconductor Josephson junctions, where the metal is Mo, Co, or a CuxNi1−x alloy, and GaN light-emitting diodes. In addition, Tl2Ba2CaCu2O8 intrinsic Josephson junctions were also fabricated and characterized. The flexibility of the FIB technique allowed junctions of many different materials and heterostructures to be fabricated with the same process.
TL;DR: In this paper, the patterning of a metallic mask by focused ion beam (FIB) etching and the pattern transfer to an underlying metallic electrode by dry etching is proposed.
TL;DR: In this article, a diamond-like carbon (DLC) mold fabricated by focused ion-beam chemical vapor deposition (FIB-CVD) using a precursor of phenanthrene has been applied to a nano-print process.
Abstract: Three-dimensional diamond-like carbon (DLC) mold fabricated by focused-ion-beam chemical vapor deposition (FIB-CVD) using a precursor of phenanthrene has been applied to a nanoimprint process. Various 3D nanostructure DLC molds have been delineated by FIB-CVD using a computer-controlled pattern generator which is a commercially available pattern generator for electron beam lithography. Then, the molds were imprinted into hydrogen silsequioxane (HSQ) as a material replicated at room temperature. It was confirmed that the 3D mold, after nanoimprint lithography (NIL), kept its original shape, and 3D mold structures were successfully imprinted into HSQ. These results reveal that the 3D mold fabricated by FIB-CVD can be applied to NIL.