Showing papers on "Focused ion beam published in 1990"

Charged Particle Beams

Abstract: Phase Space Description of Charged Particle Beams Introduction to Beam Emittance Beam Emittance - Advanced Topics Introduction to Beam-Generated Forces Beam-Generated Forces - Advanced Topics Electron and Ion Guns High Power Pulsed Electron and Ion Diodes Paraxial Beam Transport with Space-Charge High Current Electron Beam Transport in Vacuum Ion Beam Neutralization Electron Beams in Plasmas Transverse Instabilities Longitudinal Instabilities Energy Extraction from Beams.

Focused ion beam induced deposition of platinum

Abstract: Focused ion beam induced deposition of platinum from a precursor gas of (methylcyclopentadienyl)trimethyl platinum has been demonstrated. This organometallic compound is solid at room temperature with a vapor pressure of 0.054 Torr. Ga+ ions at 30–40 keV have been used. The resistivity and composition of the film and the deposition yield have been measured as a function of ion current density, line dose, substrate temperature, geometry, and supplemental hydrogen pressure. Yield varies from 0.2 to 34, and resistivity varies from 70 to 700 μΩ cm depending on the conditions. The resistivity and content of the carbon impurity are reduced as the ion current increases: the lowest resistivity is observed at the highest current density corresponding to 0.222 nA at scan speed 500 cm/s repeated over a 350 μm long line. The minimum linewidth achieved so far is 0.3 μm. Transmission electron microscopy shows the Pt film to be amorphous, and Auger analysis gives the film composition 46% Pt, 24% C, 28% Ga, and 2% O. The...

Ion beam induced deposition of metals

Abstract: Metal is deposited in lines of submicron width by scanning a focused ion beam along a substrate in the presence a vapor of a precursor platinum compound. High deposition rates and steep walls may be obtained by milling a cavity or trench with the focused beam and then locally applying the precursor vapor while scanning of the beam continues. Platinum containing features deposited in this way extend horizontally between wires, or vertically between layers to form conductive interconnects in integrated circuits, and also form pattern repairs in x-ray masks. The platinum chemistry is compatible with silicon wafer processing.

X‐ray mask repair with focused ion beams

Abstract: The application of focused ion beams to the repair of defects in x‐ray masks is described. An image of the defective region on the mask is obtained using the ion beam in a manner analogous to a scanning electron microscope. Opaque defects are removed by physical sputtering of extra absorber. Clear defects are repaired by ion‐beam‐induced decomposition of an organometallic compound to form an opaque film on the substrate. Examples illustrating the repair process and demonstrating submicron spatial resolution are presented. The effect of ion channeling on imaging and opaque repair is also described.

Fabrication of Planar and Cross-Sectional TEM Specimens Using a Focused Ion Beam

Abstract: A new technique using a focused ion beam has been developed for the fabrication of transmission electron microscopy specimens in pre-selected regions. The method has been proven in the fabrication of both cross-sectional and planar specimens, with no induced artefacts. The lateral accuracy achievable in the selection of an area for cross-sectional analysis is better than one micrometre. The technique has been applied to a number of silicon and III-V based integrated circuits, and is expected to be suitable for many other materials and structures.

Advantages of high speed scanning for microprobe analysis of biological samples

Abstract: The damage caused by the impact of a high energy focused ion beam on biological targets can lead, in a number of cases, to erroneous analytical results. Some of the observed modifications result from cummulative radiolytic effects and cannot be avoided. However, those alterations, induced by a local increase of the sample temperature can be minimized by high speed scanning. We present here the first comparative results achieved by irradiation of organic samples by the CENBG Nuclear Microprobe for different scan frequencies.

Method of making wiring and logic corrections on a semiconductor device by use of focused ion beams

Abstract: Herein disclosed are a variety of techniques relating to the wiring and logic corrections on a chip by making use of the focused ion beam (which is shortly referred to as “FIB”) or the laser selection metal CVD. The time periods for the wiring corrections and for debugging and developing an electronic system are shortened by making use of the processing characteristics of the FIB. Illustratively, a hole is bored in an insulating film above a portion of a wiring which is to be connected to another wiring by means of a focused ion beam. The inside of the hole and a predetermined region on the insulating film are irradiated with either a laser beam or an ion beam in a metal compound gas to deposit metal in the hole and on said region and a connecting wiring is formed by means of optically pumped CVD. The present invention also relates to an IC or VLSI structure having a trial cutting region, at test etching region and an auxiliary wiring or pad, suitable for the application of such defect correction and circuit change, as well as a method of making same, a designing method using such technique, and a focused ion beam system and other systems for use in those methods.

Focused ion beam technology: a bibliography

Abstract: Focused ion beams are used in a wide range of materials characterization and manipulation techniques. This bibliography draws together approximately 1100 references describing the production, control and application of focused ion beams produced using liquid metal ion sources and gas field ion sources. The bibliography has been divided into 13 sections based on source type and application. The applications considered include ion microprobe, secondary ion mass spectroscopy, ion microscopy, lithography, microfabrication, ion beam etching, ion implantation, ion beam deposition, and ion propulsion methods. A simple study of the changing nature of this area of the literature has also been carried out.

Handbook of Ion Beam Processing Technology: Principles, Deposition, Film Modification and Synthesis

Abstract: Perspective on Past, Present and Future Uses of Ion Beam Technology Part I. Ion Beam Technology Gridded Broad-beam Ion Sources ECR Ion Sources Hall Effect Ion Sources Ionized Cluster Beam (ICB) Deposition and Epitaxy Part II. Sputtering Phenomena Quantitative Sputtering Laser-induced Fluorescence as a Tool for the Study of Ion Beam Sputtering Characterization of Atoms Desorbed from Surfaces by Ion Bombardment Using Multiphoton Ionization Detection Part III. Film Modification and Synthesis The Modification of Films by Ion Bombardment Control of Film Properties by Ion-assisted Deposition Using Broad Beam Sources Etching with Directed Beams Film Growth Modification by Concurrent Ion Bombardment: Theory and Simulation Interface Structure and Thin Film Adhesion Modification of Thin Films by Off-normal Incidence Ion Bombardment Ion Beam Interactions with Polymer Surfaces Topography: Texturing Effects Methods and Techniques of Ion Beam Processes Ion-assisted Dielectric and Optical Coatings Diamond and Diamond-like Thin Films by Ion Beam Techniques Index

Electron focusing with multiparallel one-dimensional channels made by focused ion beam

Abstract: Electron focusing effect is observed in a two‐dimensional electron gas using samples with simple multiparallel one‐dimensional channels made by a Be focused ion beam (FIB). Subharmonics and harmonics are resolved; their strengths allow a direct determination of the elastic scattering length le =1.8 μm and the specularity coefficient p=0.35 for electron reflection at the boundary defined by the FIB. The temperature dependence of the focusing effect is much weaker than the Shubnikov–de Haas effect.

Focused ion beam stimulated deposition of aluminum from trialkylamine alanes

Abstract: Focused ion beam stimulated deposition of aluminum from trimethylamine alane, a white solid, and triethylamine alane, a colorless liquid, is reported. Initiation of growth on Si and SiO2 substrates is enhanced by in situ sputter cleaning of the surface with the Ga+ beam prior to introduction of the metallo‐organic. Alternatively gas phase chemical activation with a silane coupling agent can enhance nucleation. Uniform nucleation on Al surfaces does not require any pretreatment. The Al features are electrically conducting, but incorporation of C and N from the amines leads to a resistivity approximately 300 times that of bulk Al. A qualitative model is presented that describes the balance condition for net material deposition as opposed to sputtering in terms of precursor flux and sticking probability as well as ion beam current density and beam scanning parameters. Film morphology and composition are also discussed.

Focused ion beam machining of Si, GaAs, and InP

Abstract: The focused ion beam (FIB) has been demonstrated as a precision fabrication tool for a wide variety of applications, primarily for semiconductor related processing. In order to facilitate the practical utilization of this tool, the Ga+ FIB micromachining characteristics of Si (100), Si(111), GaAs (100), and InP (100) were investigated. Rectangular wells having dimensions of 4×10×1 μm were sputtered into the above materials at 15 and 25 keV and dwell times ranging from 25 μs to 100 ms per point for a fixed total machining time. Planview and cross section scanning electron microscope examination was used to quantify sputter yield and characterize feature shapes. Sputter yield and material redeposition variations dependent on beam dwell times were observed as evidenced by changes in side wall slope, crater bottom flatness, and material redeposition.

Cross-Sectional TEM Specimen Preparation of Semiconductor Devices by Focused Ion Beam Etching

Abstract: A procedure for preparing cross-sectional TEM specimens by focused ion beam etching (FIB) of specific regions on an integrated circuit chip is outlined. The investigation of the morphology, structure and local chemistry of precisely selected regions of semiconductor devices becomes increasingly important since the lateral dimensions and layer thickness of device structures are continually being reduced. The standard technique of preparing specimens for TEM, whether planar or cross-sectional, cannot select particular small regions. Some techniques and a number of tools and fixtures have been proposed which allow us to prepare TEM specimen of prespecified locations in complex devices. Most of these techniques, however, are still very difficult, tedious process and time consuming. p]A new technique has been proposed recently involving the use of FIB. The technique ensures that the preselected area of submicron scale will be located in the electron transparent section used for TEM imaging, in preparation turn-around time of about two hours. The TEM imaging of specific contacts via hole in a VLSI chip is illustrated.

Elliptical ion beam distribution method and apparatus

Abstract: An ion source (10) for creating an ion beam. The source includes an ionization chamber (16) having one wall that defines a generally elliptical opening (50) for allowing ions to exit the ionization chamber. Use of an elliptical (in section) ion beam has advantages over a rectangular ion beam which allow the integrity of a relatively high current ion beam to be maintained as ions travel to a beam treatment workstation. A dual configuration extraction electrode assembly (20) also provies for a range of extraction energies from a single source.

Focused ion beam channeling effects and ultimate sizes of GaAlAs/GaAs nanostructures

Abstract: We show that focused ion beam implantation of Ga into GaAlAs/GaAs quantum wells occurs much deeper than expected from theory of implantation into amorphous GaAs and that the lateral straggling is one order of magnitude smaller than predicted by the same theories. We show that channeling is the main mechanism involved in these effects. The small probe size achieved with the focused ion beam is thus preserved 200 nm below the surface.

Micromachining and Device Transplantation Using Focused Ion Beam

Abstract: During the past ten years, a number of focused ion beam (FIB) applications in microelectronics have been demonstrated and steadily identified. In this paper, we will review FIB micromachining and device transplantation, in which processes of FIB sputtering, redeposition, and/or FIB-assisted deposition are well utilized. The FIB 3-dimensional micromachining is demonstrated with the aid of a sample rotator. Good prospects in the device transplantation are identified as a new high-resolution method for microdevice assembly and device repair. These FIB applications can be visually performed using scanning ion microscope (SIM) images. Specifications of the FIB apparatus for these applications and FIB micromachining simulation are also discussed.

Pulse‐periodical high‐intensity ion sources for multielement implantation

Abstract: In this paper we present results on the formation of multicomponent ion beams with controlled composition for ion implantation. The principles of control of the beam composition and energy are formulated by consideration of the requirements of beams for multielement ion implantation. It is shown that variation of the composition and energy can be obtained by repetitively pulsed beam formation with spatial separation of the different components. Results are presented of different versions of our high current ion sources, and of the means for controlling the beam composition and energy on a pulse‐to‐pulse basis and also within each pulse.

Low Energy Focused Ion Beam System and Application to Low Damage Microprocess

Abstract: We have developed a low energy focused ion beam (FIB) system by employing retarding field optics. The system is equipped with a gas jet and is used for ion beam assisted etching or deposition. To evaluate the usefulness of low energy FIB, we have been investigating defects in GaAs induced by irradiation of low energy Ga+ FIB and Ar+ unfocused beams. Defets induced by irradiation at 300 K were observed even at a depth of >2000 ?, which is much deeper than the ion range. However, it was observed that the deep distribution was suppressed by irradiation at low temperature (100 K.

Vacuum lithography for in situ fabrication of buried semiconductor microstructures

Abstract: We have developed a complete lithographic process combining focused ion beam writing, dry etching, and molecular beam epitaxy for in situ preparation of buried InP‐based microstructures. A focused ion beam is used to locally remove an ultrathin oxide imaging layer grown in situ on the surface of InP. The pattern is transferred into the underlying semiconductor by free Cl2 etching with the patterned oxide layer acting as an etch mask. After removal of the oxide mask, GaInAs/InP heterostructures with excellent morphology and high luminescence efficiency can be grown on the patterned substrate. The entire process of mask formation, lithography, and regrowth can be carried out in situ repeatedly, and used for creating fully buried microstructures.

Reduction of induced damage in GaAs processed by Ga+ focused‐ion‐beam‐assisted Cl2 etching

Abstract: Damage in GaAs induced by Ga+ focused‐ion‐beam‐assisted Cl2 etching is studied by photoluminescence (PL) intensity measurements as functions of ion energy, ion dose, and substrate temperature. By decreasing the ion energy from 10 to 1 keV, the damage depth decrease to 1/5, where damage depth is taken as the thickness at which the PL intensity recovers by wet etching. The damage depth is shallower when the etching yield is larger with the same ion energy. By increasing the ion dose, the normalized PL intensity decreases, but damage depth is nearly constant. Over 1015 ion dose, the normalized PL intensity shows a constant value. By increasing the sample temperature, the damage depth becomes shallower. At 150 °C with ion energy of 1 keV, the damage depth is less than 0.5 μm, which is the detection limit of the PL measurement in GaAs substrate.

Charged particle beam pattern generation apparatus and method

Abstract: A pattern control system and method for a charged particle beam such as a focused ion beam (FIB) (20) or electron beam writes beam patterns on a pixel-by-pixel (56) basis. Respective dwell times and beam blanking states are specified for each separate pixel location (56), enabling the creation of arbitrary patterns and various implantation gradients. Pixel commands are generated by a central processing unit (CPU) (104), which can be relieved by hardware pattern generators (FIG. 10) for frequently used patterns. The system also includes improvements in stigmation control, fiducial mark recognition and the reconciliation of the beam and target coordinate systems.

Particle beam shielding

Abstract: An apparatus is described for allowing an ion beam and an electron beam to travel toward a predetermined region of a substrate surface during the sputter etching and imaging of insulating and other targets while preventing deflection of the electron beam by sources of stray electrostatic fields on the substrate surface. A metal shield is provided having a funnel-shaped portion leading to an orifice. The incident finely focused ion beam, together with the electron beam, which is used to neutralize the charge created by the incident ion beam, pass to the target through the orifice. The shield also physically supports a gas injection needle that injects a gas through the orifice toward the predetermined region.

Beam‐size measurements in focused ion beam systems

Abstract: Accurate measurement of the beam diameter for a finely focused ion beam is difficult using conventional methods which have been applied in electron beam systems. Generally, the beam is scanned across an abrupt edge while measuring beam current or secondary electron intensity. For ions, the sputtering of the sample degrades the shape of the edge and thus the accuracy of the measurement. Furthermore, implantation can change the secondary electron contrast during the measurement. In this paper, a new method is suggested that avoids these difficulties. The ion beam diameter is determined by measuring the ratio of ion flux in a single pixel wide feature to that of a feature which is much larger than the beam diameter. This ratio can be measured using a threshold process. For this paper, we have used sputtering of a thin film as the threshold process and secondary ion mass spectrometry as the end‐point determinant.

Focused ion beam micromachined three‐dimensional features by means of a digital scan

Abstract: Focused ion beam micromachining (FIBM) is a promising new technique capable of forming optical quality surfaces in semiconductor laser materials. A beam of 25 keV Ga+ ions focused to a 50–250 nm spot can sputter materials from a wafer surface providing a method for fabricating submicron features, such as diode laser output mirrors and coupled cavity oscillating mirrors. To date, all mirrors fabricated by traditional FIBM have been made up of lines or rectangles (i.e., fabricated by straight line scans). However, straight line scans cannot be satisfactorily used for many kinds of applications. In order to fabricate arbitrary structures such as curves and intersecting lines, a fully digitized, nonlinear, three‐dimensional (3D) and variable‐speed scan strategy, which can produce desired structures with arbitrarily curved paths in a plane and arbitrary depth profiles, has been developed. This strategy has been implemented using a FIB system with an IBM‐compatible computer to fabricate ‘‘V’’, micro‐‘‘V’’ and p...

Magnetic head and production thereof

Abstract: PURPOSE: To improve the noise characteristic occurring in adjacent tracks by providing one or more grooves in a part of a surface for sliding with media and processing the grooves by focused ion beam etching. CONSTITUTION: The material of magnetic poles 102 is 'Permalloy(R)' having 1.0T saturation magnetic flux density, the materials of a gap layer 104 and a protective layer 103 are alumina and the material of a slider 101 is zirconia. Local recessed parts are provided near a magnetic gap 104 or magnetosensitive part of the magnetic head and the widths thereof are regulated. These grooves or recessed parts are processed by the focused ion beam (FIB) and a material is preferably packed into these grooves or recessed parts. The magnetic head of a narrow track having excellent offtrack characteristics is obtd. in this way. COPYRIGHT: (C)1991,JPO&Japio