Showing papers on "Focused ion beam published in 2002"
TL;DR: In this paper, a detailed study on the acceleration of intense ion beams by relativistic laser plasmas was performed at the 100 TW laser at the Laboratoire pour L'Utilisation des Lasers Intenses.
Abstract: We present the results of a detailed study on the acceleration of intense ion beams by relativistic laser plasmas. The experiments were performed at the 100 TW laser at the Laboratoire pour L'Utilisation des Lasers Intenses. We investigated the dependence of the ion beams on the target conditions based on theoretical predictions by the target normal sheath acceleration mechanism. A strong dependence of the ion beam parameters on the conditions on the target rear surface was found. We succeeded in shaping the ion beam by the appropriate tailoring of the target geometry and we performed a characterization of the ion beam quality. The production of a heavy ion beam could be achieved by suppressing the amount of protons at the target surfaces. Finally, we demonstrated the use of short pulse laser driven ion beams for radiography of thick samples with high resolution.
216 citations
TL;DR: In this article, a focused ion-beam milling-based sample geometry was developed for a range of sample thicknesses and bias voltages to allow the holographic contrast to be interpreted and the physical and electrical nature of the sample surface, which is affected by sample preparation and electron beam irradiation, was discussed.
Abstract: Electron holography is used to measure electrostatic potential profiles across reverse-biased Si p-n junctions in situ in the transmission electron microscope. A novel sample geometry based on focused ion-beam milling is developed, and results are obtained for a range of sample thicknesses and bias voltages to allow the holographic contrast to be interpreted. The physical and electrical nature of the sample surface, which is affected by sample preparation and electron beam irradiation, is discussed.
158 citations
TL;DR: In this article, electron beam lithography and focused ion beam (FIB) were combined to make low-resistance ohmic contacts to individual bismuth nanowires.
Abstract: Techniques are presented for making ohmic contacts to nanowires with a thick oxide coating. Although experiments were carried out on Bi nanowires, the techniques described in this paper are generally applicable to other nanowire systems. Metal electrodes are patterned to individual Bi nanowires using, electron beam lithography. Imaging the chemical reaction on the atomic scale with in situ high-resolution transmission electron microscopy shows that annealing in H-2 or NH3 can reduce the nanowires' oxide coating completely. The high temperatures required for this annealing, however, are not compatible with the lithographic techniques. Low-resistance ohmic contacts to individual bismuth nanowires are achieved using a focused ion beam (FIB) to first sputter away the oxide layer and then deposit Pt contacts. By combining electron beam lithography and FIB techniques, ohmic contacts stable from 2 to 400 K are successfully made to the nanowires. A method for preventing the burnout of nanowires from electrostatic discharge is also developed.
140 citations
Patent•
27 Jul 2002TL;DR: In this article, a method and apparatus for electron beam processing using an electron beam (101) activated gas to etch or deposit material was presented, particularly suitable for repairing defects in lithography masks.
Abstract: A method and apparatus for electron beam processing using an electron beam (101) activated gas to etch or deposit material. The invention is particularly suitable for repairing defects in lithography masks. By using an electron beam (101) in place of an ion beam, the many problems associated with ion beam mask repair, such as staining and riverbedding, are eliminated. Endpoint detection is not critical because the electron beam and gas will not etch the substrate. In one embodiment, xenon ditluoride gas is activated by the electron beam (101) to etch a tungsten, tantalum nitride, or molybdenum silicide film on a transmission or reflection mask. To prevent spontaneous etching by the etchant gas in processed sites at which the passivation layer was removed, processed sites can be re-passivated before processing additional sites.
138 citations
Book•
31 Oct 2002
TL;DR: In this article, the authors present a theoretical analysis of focused ion beams and their application in the field of field ionization and field desorption, as well as practical applications of Focused Ion Beam Optics and Systems.
Abstract: Preface. About the Authors. Introduction. 1. Field Ionization Sources. 2. Physics of Liquid Metal Ion Sources. 3. Ion Optics for LMIS. 4. Interactions of Ions with Solids. 5. Practical Focused Ion Beam Optics and Systems. 6. Applications of Focused Ion Beams. Appendix 1. Elements of the Theory of Field Desorption and Ionization. Appendix 2. Table of Sputter Yields. Index.
132 citations
TL;DR: The role of imperfections on the initiation and propagation of buckle driven delaminations in compressed thin films has been demonstrated using experiments performed with diamond-like carbon (DLC) films deposited onto glass substrates as discussed by the authors.
115 citations
TL;DR: In this article, an experimental set-up is presented, that allows in situ scanning electron microscope (SEM) investigations of the progress of electromigration damage in fully embedded copper interconnect structures.
97 citations
TL;DR: In this paper, a planar magnetic element with high magnetic shape anisotropy, an extremely high aspect ratio of greater than 30:1, and an end radius of less than 25 nm was used for magnetic force microscopy.
Abstract: Atomic force microscope tips coated by the thermal evaporation of a magnetic 30 nm thick Co film have been modified by focused ion beam milling with Ga+ ions to produce tips suitable for magnetic force microscopy. Such tips possess a planar magnetic element with high magnetic shape anisotropy, an extremely high aspect ratio of greater than 30:1, and an end radius of less than 25 nm. These tips have been used in a commercial atomic force microscope under ambient conditions to obtain 30 nm resolution magnetic images of an established CoNi/Pt multilayer reference sample.
86 citations
TL;DR: A focused ion beam (FIB) instrument has been used to mill surfaces in singlecrystal Si and single-crystal Cu for subsequent electron backscattering diffraction (EBSD) analysis as discussed by the authors.
Abstract: A focused ion beam (FIB) instrument has been used to mill surfaces in single-crystal Si and single-crystal Cu for subsequent electron backscattering diffraction (EBSD) analysis. The FIB cuts were performed using a 30 keV and a 5 keV Ga+ ion beam at a stage tilt of 20° to provide a readily obtainable 70° surface for direct EBSD investigation in a scanning electron microscope (SEM). The quality of the patterns is related to the amount of FIB damage induced in the Cu and Si. These or similar methods should be directly transferable to a FIB/SEM dual beam instrument equipped with an EBSD detector.
81 citations
TL;DR: A focused ion-beam (FIB) technique utilizing both lithographic and nanoparticle formation processes has been introduced to fabricate a single-electron transistor (SET) that can operate at room temperature.
Abstract: A focused-ion-beam (FIB) technique utilizing both lithographic and nanoparticle formation processes has been introduced to fabricate a single-electron transistor (SET) that can operate at room temperature. The results for the drain current as a function of the gate voltage at different source voltages at room temperature clearly show Coulomb oscillations indicative of Coulomb-blockade effects. These results indicate that SETs operating at room temperature, fabricated utilizing the FIB technique, hold promise for potential applications in ultra-high-density memory devices.
78 citations
TL;DR: In this paper, an extremely miniaturized pressure sensor called nano-pirani is reported, whose active area is a mere 10 μm × 1 ǫμm.
Abstract: This paper reports an extremely miniaturized pressure sensor. In its smallest version, the sensor’s active area is a mere 10 μm ×1 μm. The sensor’s working principle is that of Pirani-type vacuum sensors. However, unlike most Pirani sensors, the working range of the device is around atmospheric pressure. The NanoPirani is fabricated exclusively by a combination of focused ion beam (FIB) deposition and milling. FIB fabrication enables rapid prototyping of this type of surface micromachined devices, as well as flawless integration with electronics. Besides the fabrication sequence, the first experimental results are presented.
TL;DR: In this article, the effect of ion damage on the properties of 50 keV Ga+ focused ion beam fabricated lead-zirconate-titanate capacitors as a function of the ion dose was studied.
Abstract: We studied the effect of ion damage on the properties of 50 keV Ga+ focused ion beam fabricated lead-zirconate-titanate capacitors as a function of the ion dose. We observed significant modification in the chemical composition of the damaged layer due to loss of lead and oxygen, and gallium impurity accumulation. The 5–10 nm thick damaged layer becomes dielectric after annealing and does not recover its ferroelectric properties. This dielectric layer substantially reduces the actual volume of the ferroelectric material in sub-100 nm structures, and can affect their performance.
TL;DR: In this paper, a cross-sectional sample of a silicon-metal-oxide semiconductor field effect transistor, which was directly cut from an integrated circuit wafer, has been prepared carefully using a focused ion-beam technique and examined by means of off-axis electron holography.
Abstract: A cross-sectional sample of a silicon-metal-oxide semiconductor field-effect transistor, which was directly cut from an integrated circuit wafer, has been prepared carefully using a focused-ion-beam technique and examined by means of off-axis electron holography. In the reconstructed phase image, heavily doped source, and drain regions are revealed clearly as bright contrast, from which an n-channel transistor is identified. In addition, two-dimensional phase distributions around both source and drain regions show a core area with relatively high phase in the heavily doped region, which may be attributed to the effect of doping atoms and residual defects and strains remaining after implantation. The electrostatic potentials across the core area and depletion layer are estimated and discussed. This work demonstrates the feasibility of using a focused-ion-beam technique to prepare electron holographic sections of a wide range of semiconductor devices.
TL;DR: In this article, the effects of Ga+ ion flux and precursor flux on the deposited films' composition and resistivity were determined, showing that increasing precursor flux at constant ion flux increases Pt and C, but decreases Ga content of the film.
Abstract: This work presents results from the characterization of ion-assisted chemical vapor deposition of platinum from trimethyl–methylcyclopentadienyl–platinum (C9H16Pt). Films were deposited in squares ranging from 50 to 200 μm on a side using a focused ion beam system. The effects of Ga+ ion flux and precursor flux on the deposited films’ composition and resistivity were determined. Films were characterized using atomic force microscopy, Rutherford backscattering spectrometry, and Auger electron spectroscopy. Results show that increasing precursor flux at constant ion flux increases Pt and C, but decreases Ga content of the film. Increasing ion flux at constant precursor flux increases Pt content, while decreasing C content of the films. Resistivity did not depend on the thickness of 50–200 nm thick films. Resistivity was shown to follow C content, with films with lower C content having lower resistivity.
Patent•
30 Aug 2002
TL;DR: In this article, the authors describe an electron beam system based on a plasma generator in a plasma ion source with an accelerator column, where the electrons are extracted from a plasma cathode in a plasminar ion source.
Abstract: An electron beam system is based on a plasma generator in a plasma ion source with an accelerator column. The electrons are extracted from a plasma cathode in a plasma ion source, e.g. a multicusp plasma ion source. The beam can be scanned in both the x and y directions, and the system can be operated with multiple beamlets. A compact focused ion or electron beam system has a plasma ion source and an all-electrostatic beam acceleration and focusing column. The ion source is a small chamber with the plasma produced by radio-frequency (RF) induction discharge. The RF antenna is wound outside the chamber and connected to an RF supply. Ions or electrons can be extracted from the source. A multi-beam system has several sources of different species and an electron beam source.
Patent•
03 Dec 2002
TL;DR: In this article, the columnar tip is grown from the cantilever portion at an angle shifted by an angle at which the probe portion is inclined during scanning of the sample surface.
Abstract: A probe for a scanning probe microscope has a cantilever portion and a microscopic probe portion formed of a solid columnar tip at a distal end of the cantilever portion by deposition using an organic gas decomposed by a focused ion beam inside a vacuum chamber. The probe is sufficiently narrow and has high abrasion resistance and rigidity. The tip may be grown to extend from the cantilever portion at an angle shifted by an angle at which the cantilever portion is inclined during scanning of the probe portion across a sample surface, so that the columnar tip is perpendicular to the sample surface during the scanning. The tip may be formed of a conductive material such as tungsten of diamond-like carbon by FIB-CVD.
TL;DR: In this paper, a scanning probe capable of simultaneously measuring topography and local electrochemistry at a sample surface is proposed, which is achieved by integrating micro-and nanoelectrodes into atomic force microscopy tips using focused ion beam techniques.
Abstract: This paper concerns a scanning probe capable of simultaneously measuring topography and local electrochemistry at a sample surface. Our approach ensures the distance regulation of the electrode by maintaining a fixed working distance between the probe and the sample surface independent from the electrochemical response. This is achieved by integrating micro- and nanoelectrodes into atomic force microscopy tips using focused ion beam techniques. The feasibility and functionality of the fully featured tip is demonstrated by a simultaneous topographical and electrochemical measurement of a porous polymer membrane as model surface.
TL;DR: In this paper, cross-section transmission electron microscopy (TEM) was used to compare (100) Si substrates on which Pt metal lines have been grown by ion-and electron-beam assisted CVD processes.
Abstract: Dual-beam instruments incorporate both an electron column and an ion column into a single instrument, and therefore allow the chemical vapor deposition (CVD) process to be either ion- or electron-beam assisted. Damage has been observed in the surface layers of specimens in which ion-beam assisted CVD processes have been employed. Cross-section transmission electron microscopy (TEM) has been used to compare (100) Si substrates on which Pt metal lines have been grown by ion- and electron-beam assisted CVD processes. The micrographs show that a 30 keV Ga+ ion beam, a 5 keV ion beam, and a 3 keV electron beam imparts 50 nm, 13 nm, and 3 nm of damage to the Si substrate, respectively. In addition, Au–Pd and Cr sputter coatings were evaluated for the prevention of ion-beam induced surface damage. TEM cross-section specimens revealed that Cr sputter coatings > 30 nm in thickness are sufficient to protect the (100) Si surface from the 30 keV Ga+ ion beam while Au–Pd sputter coatings up to 70 nm in thickness may b...
TL;DR: In this paper, a photoactive layer of poly[2-methoxy-5-(3′,7′-dimethyl octyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and a C60 derivative, (1-(3methoxcarbonyl)propyl-1-phenyl-[6,6]-methanofullerene), (PCBM), sandwiched between an indium tin oxide (ITO) anode covered with poly(ethylene dioxythiophene):poly(
Abstract: Bulk-heterojunction photovoltaic cells consisting of a photoactive layer of poly[2-methoxy-5-(3′,7′-dimethyloctyloxy)-1,4-phenylenevinylene] (MDMO-PPV) and a C60 derivative, (1-(3-methoxycarbonyl)propyl-1-phenyl-[6,6]-methanofullerene), (PCBM), sandwiched between an indium tin oxide (ITO) anode covered with poly(ethylene dioxythiophene):poly(styrene sulfonate) (PEDOT:PSS), and an aluminum cathode have been analyzed using transmission electron microscopy (TEM) and cryogenic Rutherford backscattering spectrometry (RBS) to assess the structural and elemental composition of these devices. TEM of cross sections of fully processed photovoltaic cells, prepared using a focused ion beam, provide a clear view of the individual layers and their interfaces. RBS shows that during preparation diffusion of indium into the PEDOT:PSS occurs while the diffusion of aluminum into the polymer layers is negligible. An iodinated C60 derivative (I-PCBM) was used to determine the concentration profile of this derivative in the vertical direction of a 100 nm active layer.
TL;DR: In this article, a direct measurement of magnetization switching indicating zero-magnetization remanence in a magnetic probe with a cross section as narrow as 60×60nm2, and as tall as 750 nm, is presented.
Abstract: In this letter, a direct measurement of “easy” magnetization switching indicating zero-magnetization remanence in a magnetic probe with a cross section as narrow as 60×60 nm2, and as tall as 750 nm, is presented. Magnetic force microscopy was utilized to test focused-ion-beam-fabricated nanomagnetic probes. The data directly indicate that unlike a regular solid probe, a probe with a tubelike ending (nanotube) provides substantially “easier” switching.
TL;DR: In this article, the surface deviation relative to the unimplanted case as a function of dose for the radial positions of interest, and determine scaling factors for the dose such that the scaled curves coincide for all radial positions in the regions of small milling depths.
Abstract: An approach to the profile extraction of nanoscale focused ion beams is presented. It is based on contour profiling of dots patterned at various ion doses by focused ion beam exposure. While the surface contour depends on the spatial variation of the beam-solid interaction, at no single ion dose the contour reflects the current density profile of the beam itself, due to effects such as target swelling, redeposition, and angle-dependent sputtering yield. Instead, we monitor the surface deviation relative to the unimplanted case as a function of dose for the radial positions of interest, and determine scaling factors for the dose such that the scaled curves coincide for all radial positions in the regions of small milling depths. We apply the method to beam shape determination of 10 and 50 keV focused ion beams using silicon and GaAs as targets and atomic force microscopy as a contour profiling technique. Despite the different irradiation response of silicon and GaAs, the beam profiles evaluated on these substrate materials agree excellently, which demonstrates that our approach is substrate independent. It allows profile extractions of nanoscale focused ion beams with high accuracy and high sensitivity even in the tails of the beams.
TL;DR: In this article, the authors measured the mechanical resonant frequency and spring constant of amorphous carbon nanopillars grown by focused ion beam assisted chemical vapor deposition (FIB CVD) to evaluate the pillar density.
Abstract: The mechanical resonant frequency and spring constant of amorphous carbon nanopillars grown by focused ion beam assisted chemical vapor deposition (FIB CVD) were measured to evaluate the pillar density. The measured density ranged from 2.5 to 4.2×3 kg/m3, depending on the growth conditions. Annealing the pillars at 600 °C completely removed the Ga incorporated in the pillar during FIB CVD. The pillar density after annealing decreased to about 1.9×103 kg/m3, which indicated the density excess was mainly due to the implantation of Ga. At lower growth rates, a sharp decrease in the Ga content suggested higher sputtering rate of Ga through ion beam irradiation.
TL;DR: In this paper, the use of the focused ion beam (FIB) technique for cross-sectional transmission electron microscopy (TEM) specimen preparation of polymer solar cells deposited on glass substrates is described.
TL;DR: In this article, cross-sections through nanoindentions in the (001) surface of sapphire, spinel and magnesia have been examined in the transmission electron microscope.
Abstract: Cross-sections through nanoindentions in the (001) surface of sapphire, spinel and magnesia have been examined in the transmission electron microscope. Electron-transparent sections were prepared using a focused ion beam microscope. All three recognized high-temperature slip systems were observed in sapphire, while spinel deformed in slip bands on the {111} planes. Evidence was obtained for slip on {110} planes in magnesia and the possibility that slip also occurs on {100} planes is discussed as an explanation of its high ratio of hardness to yield stress.
TL;DR: In this paper, the authors outline some of the possible applications of nanotechnology to modern molecular biology and discuss several technologies that can be used to make nanoscale confining environments (channels or post arrays) for long polymers such as DNA.
Abstract: We outline some of the possible applications of nanotechnology to modern molecular biology and discuss several technologies that can be used to make nanoscale confining environments (channels or post arrays) for long polymers such as DNA. A particular emphasis is placed on making large arrays using non-electron beam lithography methods. We then discuss how focused ion beam (FIB) milling can be used to construct nearfield slits for examining molecules.
TL;DR: In this article, a refractive semiconductor micro-lenses using a focused ion beam (FIB) direct writing technique was fabricated using a simple one-step FIB process.
Abstract: We fabricated a refractive semiconductor micro-lenses using a focused ion beam (FIB) direct writing technique. The simple one-step FIB process produced high-quality micro-lenses of silicon, the most popular and low cost semiconductor material used in optoelectronics. A spherical Si microlens with a nominal lens diameter of 48 /spl mu/m exhibited a radius curvature and focal length of 100 and 40 /spl mu/m, respectively. The maximum derivation between the measured and designed profiles is less than /spl lambda//100. The surface roughness, RMS, measured by use of atomic force microscope in 1/spl times/ 1 /spl mu/m/sup 2/ square area, is 1.1 nm. This microlens fabrication method could be readily applicable due to the simplicity in processing and the high-quality results.
TL;DR: In this article, the structural changes of a Ni-P amorphous alloy under focused-ion-beam (FIB) irradiation have been examined using transmission electron microscopy, where the formation of crystallographically orientated nanosized crystals (NCs) with the particle size of approximately 10 nm was observed.
Abstract: Structural changes of a Ni–P amorphous alloy under focused-ion-beam (FIB) irradiation have been examined using transmission electron microscopy. On the irradiated plane, the formation of crystallographically orientated nanosized crystals (NCs), with the particle size of approximately 10 nm, was observed. A series of electron diffraction analyses have revealed that NCs have a face-centered-cubic (fcc) structure and the following orientation relationships between the NCs and the FIB direction were found. These are, irradiated plane//(111)fcc and FIB direction//〈110〉fcc.
05 Jul 2002
TL;DR: In this article, an e-beam-induced chemical etching for opaque defect removal and metal deposition for clear defect repair is presented. But, the results are limited to phase shift masks.
Abstract: Substrate damage from Ga ions is a fundamental problem of using focused ion beam (FIB) for mask defect repair. One way to avoid substrate damage from repair is to replace Ga ions with electrons. In this paper, we describe our efforts and present some promising results that demonstrate the feasibility of using e-beam induced processes for mask repair. We employ e-beam induced chemical etching for opaque defect removal and metal deposition for clear defect repair. The examples will include Pt deposition, quartz etch for phase-shift mask and TaN etch for EUV mask. High-resolution electron beam technology is relatively mature, so the infrastructure for building an e-beam system suitable for mask repair exists today. This makes the development of an e-beam based damage-free repair technology attractive. E-beam also offers superior spatial resolution for high edge placement precision and image quality for small defects on ever shrinking mask features.
Patent•
26 Jun 2002
TL;DR: An ion source configured for integration into both existing ion implanters used in semiconductor manufacturing and emerging ion implantation platforms is presented in this article, which includes the following features, all of which depart from the prior art to produce a well-focused, collimated and controllable ion beam.
Abstract: An ion source configured for integration into both existing ion implanters used in semiconductor manufacturing and emerging ion implantation platforms. The ion source in accordance with the present invention includes the following features, all of which depart from the prior art to produce a well-focused, collimated and controllable ion beam. These features include: ionizing electron beams generated external to the ionization chamber, thereby extending the emitter lifetime; 90 degree magnetic deflection of electron beams such that no line-of-sight exists between the emitter and the process gas load, and the emitter is protected from bombardment by energetic charged particles; two opposed electron beams which can be operated simultaneously or separately; and use of a deceleration lens to adjust the final energy of the electron beam, substantially without affecting electron beam generation and deflection.
TL;DR: In this paper, focused ion-beam (FIB) optics in single-ion implantation (SII), which enables us to implant dopant ions one-by-one into a fine semiconductor region until the necessary number is reached, has been modified in order to improve the controllability of dopant atom position to within 100 nm.
Abstract: Focused ion-beam (FIB) optics in single-ion implantation (SII), which enables us to implant dopant ions one-by-one into a fine semiconductor region until the necessary number is reached, has been modified in order to improve the controllability of dopant atom position to within 100 nm. The lateral magnification of the objective lens (OL) was remodeled to 1/19 from the original value of 1/6 before modification. Scanning ion microscope (SIM) images at a high magnification of 75,000 were taken using a 60 keV focused Si ion beam with a current of 1 pA to evaluate the resolution of secondary electron images. A diameter of the ion beam less than of 20 nm was obtained. One-by-one, 60 keV Si ions were implanted by means of SII into CR-39 which is a fission track detector for investigating the aiming precision. Deviation of the single ion incident site from the target position was evaluated using atomic force microscopy (AFM) and compared with that before modification of FIB optics. The average aiming precision in SII was improved to be 60 nm which was 1/3 of that before modification.