Showing papers on "Focused ion beam published in 1982"

Electron beam technology

Abstract: Initially designed for scientific research, the first electron accelerators used for industrial purpose were installed in the 1950s. Electron beam accelerators are now used in diverse industries chiefly to enhance the physical and chemical properties of materials. Cross-linking of polymers used for wires, cables and heat-shrinkable products is a major application. Accelerated electrons are also used to inactivate microorganisms or to reduce the quantity of pathogens or toxic by-products in polluted waters. factsheet Over the last two decades the number of electron accelerators in use has dramatically increased.

Analysis of polymer surfaces by SIMS 1. An investigation of practical problems

Abstract: Secondary ion mass spectrometry has the potential for high spatial resolution surface analysis of polymers via fingerprint mass spectra and the use of a focused ion beam. Several problems stand in the way of realizing this potential, namely: (a) the expected high rate of ion beam damage, (b) the need for charge neutralization leading to (c) the uncertainty of surface potential and (d) the possibility of electron stimulated desorption of secondary ions. The importance of these effects have been studied using a model short chain hydrocarbon and films of polystyrene and polytetrafluoroethylene.

Reactive Ion Beam Etching Using a Broad Beam ECR Ion Source

Abstract: A broad beam ion source using a microwave electron cyclotron resonance (ECR) discharge has been newly developed, giving high reliability in operation. The ion source operates at gas pressures higher than about 3×10-5 Torr, and an ion current density of 1 mA/cm2 is obtained at an ion extraction voltage of 1000 V. By introducing C4F8 and SiCl4 into the ion source, SiO2 and Al are etched at rates greater than 1000 A/min, with high selectivities and high-accuracy pattern transfer.

Ion beam processing apparatus and method of correcting mask defects

Abstract: Disclosed is an ion beam processing apparatus comprising within a vacuum container a specimen chamber with a table for mounting a specimen provided therein, a high intensity ion source, such as a liquid metal ion source or an electric field ionizing ion source which operates in ultra-low temperature, confronting the specimen chamber, an extraction electrode for extracting an ion beam out of the ion source, a charged-particle optical system for focusing the ion beam to a spot, and an aperture for adjusting the spot diameter.

Processing method using a focused ion beam

Abstract: A processing method using a focused ion beam is proposed which uses a focused ion beam radiation apparatus. When a specimen is irradiated with the focused ion beam in order to be etched, the desired etching depth of the specimen is preset as a function of a location. The ion dose of the focused ion beam, the acceleration voltage, or the etching time may be varied in accordance with the preset data.

Reactive Ion Beam Etching with CF 4: Characterization of a Kaufman Ion Source and Details of SiO2 Etching

Abstract: Recently, the use of reactive gases in ion milling equipment has received increasing attention. We have characterized the operation of a Kaufman‐type ion source for use with , by mass spectrometric measurements of both ionic and neutral components of the beam. Fragmentation of the parent gas to ions and neutrals is found to be extensive. Fragmentation is also strongly dependent on gas pressure and on confinement of the discharge in the source due to the axial magnetic field. Previously reported dependence of etch rate on background gas pressure is examined in more detail. It is concluded that variation of ion composition does effect etch rate, but ion‐induced reaction of adsorbed neutral species is occurring. A simple mass transport model that considers adsorption and desorption processes of reagent and product species is adequate to explain the major features of the data.

Focused ion beam microfabrication column

Abstract: Focused ion beam microfabrication column (10) produces an ion beam from ion source (12), focuses the beam by objective lens (24) onto the plane of electrode (36). ExB filter (44) separates out the ion species at a low energy portion of the beam. The beam of selected species is first accelerated by pre-accelerator lens (38) which has a controllable potential for controlling the final beam energy to the target. The beam is accelerated by final accelerator lens (54) and is demagnified and focused on the target by that lens. Beam deflector (64) deflects the beam for programmed ion beam work on the target (60).

Ion Beam Assisted Maskless Etching of GaAs by 50 keV Focused Ion Beam

Abstract: Maskless etching of GaAs by means of an ion beam assisted etching technique has been investigated using a 50 keV focused Au beam, and it is found that ion beam assisted etching is very promising for maskless direct etching with a high etching rate. The Au+ focused beam was irradiated on GaAs in chlorine ambient gas. It was observed that this etching technique gives a smooth etched surface with an etching rate of 2 µmmin-1mA-1cm2, which is about 100 times larger than the value observed for physical sputter etching without chlorine gas. From the measurement of mass spectra it was observed that about 75 percent of chlorine gas reacts with residual water vapour and HCl gas is produced. It is considered that both chlorine and HCl gases play an important role in the enhancement of etching.

Ion Beam Applications For Optical Coating

Abstract: Ion beam techniques can be applied advantageously during different phases of optical coatings. Prior to deposition, substrates can be ion beam cleaned with rare gas or reactive gas ions, depending upon the substrate materials involved. During deposition, ion beam sputtering can be employed to produce films of superior optical and mechanical qualities. A hybrid technique has been demonstrated in which coating material initially is sputtered by the ion beam, and subsequently it is generated thermally due to target heating by the ion beam. In this way advantages of sputter deposition are realized during initial stages of film growth, and faster deposition rates can then be achieved using thermal generation. Another hybrid deposition technique involves ion bombardment of the optical surface while simultaneous condensation of thermally generated dielectric material occurs. Potential advantages of this technique include controlled changes of physical and chemical characteristics of the film.

Ion implantation method

Abstract: An ion implantation method is provided which uses an ion implantation apparatus which is capable of focusing an ion beam into a spot having a diameter smaller than the size of a region into which ions are to be implanted. The ion dose is varied in accordance with the gate region, source and drain regions, and the field region of a semiconductor device including a transistor having short gate length and width.

Ion beam joining technique

Abstract: Solders of various compositions are used in the electronics industry to interconnect components. To obtain proper reflow of the solder pads to be joined, surface oxides must be removed using an appropriate chemical flux. In this paper, we describe an alternative fluxless joining technique in which an ion beam is used to simultaneously sputter clean and melt solder pads prior to joining, and can also provide the heat needed to perform the joining step itself. Using a Si circuit chip with solder pads of 95% Pb, 5% Sn, the melting temperature of the solder (312 °C) is reached within 25 s in an argon ion beam of 1000 eV, 1.0 mA/cm2. The solder pads are etched about 500 A during this time, and reflow into clean spherical shapes suitable for joining. Electron microprobe analysis shows that the Pb and Sn are uniformly distributed through the solder pad after reflow. Chips have been sucessfully joined to metalized ceramic substrates using either auxiliary heating or using the heat from a focused ion beam. Pull tests show that ion beam reflowed joints are as strong as those obtained by the standard flux joining process.

Invited) Fine Focused Ion Beams

Abstract: The use of a focused ion beam for direct implantation of dopants into a semiconductor substrate results in appreciable simplification in the processing of semiconductor devices. We have demonstrated that liquid metal (LM) field-ionization sources (based upon the electrostatic formation of an emitting cusp of liquid metal) offer the necessary high brightness to make focused ion beam microfabrication feasible. This paper reports upon three developments: (1) the development of eutectic-alloy LM ion sources for the production of boron and arsenic for direct implantation of silicon devices, (2) the fabrication of a FET using a Au–Si beam that was mass separated at the target and (3) the development of a three-lens variable-energy focusing column that incorporates a mass-separator of low aberration.

Modeling ion beam milling

Abstract: Ion beam milling is a dry etching process capable of anisotropically transferring lithographic patterns from photoresist (or other mask material) into an underlying substrate. The process is conceptually simple, experimentally controllable, and therefore relatively easy to simulate on a computer. In this paper, the results of an attempt to construct a physically realistic model of ion beam milling are reported. The model explicitly demonstrates the effects of redeposition and reflected ion beam milling on the sample surface. Several comparisons of simulated profiles with real sample profiles are presented.

Resist Possibilities And Limitations In Ion Beam Lithography

Abstract: A broad range of materials and processing techniques amenable to producing resist systems for ion beam lithography are discussed. The effect of random fluctuations in exposure dose on feature size for a gaussian beam of constant shape is calculated. The results of Monte Carlo simulations of exposures of PMMA on silicon by 50 KeV H2+, 100 KeV and and 150 KeV Li+ ions are presented and it is shown that feature resolution is fundamentally limited by the physical processes through which energy is deposited.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Single grid focussed ion beam source

Abstract: A technique for providing an ion beam of variable focussing (concentration) is described using a flexible grid for extracting and accelerating ions from an ion plasma. The grid is electrically conducting and will bow depending on a voltage difference between it and the ion plasma. This bowing of the grid from its initial planar configuration provides focussing of the ion beam. The amount of focussing depends upon the amount the grid is bowed, which in turn depends upon the voltage difference between it and the ion plasma. The same ion source/flexible grid combination can be used for different operations as for example, providing a collimated, low energy ion beam over a large area and then for providing a focussed ion beam of high energy onto a small area.

The use of scanning electron microscopy to study the ion beam sputter modification of the surface topography of biological implants

Abstract: One factor which affects the biological tissue response to an implant material is the surface topography of the material. Ion beam sputtering, as a potentially useful roughening technique, has recently been used in attempts to modify the surface topography of biocompatible materials, such as metals, alloys, polymers, and ceramics. The ion-beam sputter modification of the surface topography of three different materials presently used or under consideration for implant devices were studied. A scanning electron microscope was used to examine all the materials tested.

Method and device for coating thin metallic film by vapor deposition

Abstract: PURPOSE:To improve the characteristic of a thin film by depositing a metal and metallic oxide by sputtering on the body to be vapor deposited then irradiating ion the vapor deposition part with ion beams to implant desired ions therein and controlling discretely and independently the vapor deposition by sputtering and the ion beam irradiation. CONSTITUTION:A sputtering device 18 is constituted of a magnetron sputtering source 22 and a sputtering target 24, and a metal and metallic oxide are deposited by sputtering on the body to be vapor deposited 12 from a sputtering target 24 by feeding RF or DC electric power to the source 22. On the other hand, an ion beam irradiation device 20 has an ion source 26, an ion passage pipe 28, and an ion draw-out electrode 30. The ions drawn from an ion source 26 are accelerated, scanned and controlled by means of an ion beam accelerating electrode 32 and an ion beam deflector 36, by which the ion beam is irradiated to the prescribed position of the body 12. The deposition by sputtering, the deposition by evaporation and the ion beam irradiation are discretely and independently controlled.

Ion-Channelling Effects In Scanning Microscopy And Ion Beam Writing With A 60 keV Ga+ Probe

Abstract: We describe the operation and functions of a scanning ion microscope. This has been shown capable of detecting ion-channelling phenomena in crystalline materials through the observation of crystallographic contrast in images obtained with the secondary electron and secondary ion signal. The instrument also provides on-line quantitative information on surface amorphization and on channelling effects in direct ion beam writing.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.