Showing papers on "Ion beam deposition published in 1978"

Technology of ion beam sources used in sputtering

Abstract: The technology of broad‐beam ion sources is reviewed from the viewpoint of the sputtering–deposition user. This review includes a short description of the development of discharge chambers, accelerator systems, and cathodes; the present alternatives for these components and the expected future improvements.

Localized substrate heating during ion implantation

Abstract: The enhanced etching of ion‐implanted silicon nitride in buffered hydrofluoric acid has been studied as a function of beam current in an ion implantation system using rotating mechanical scan Reduction of the enhancement due to annealing has been observed under conditions where an earlier model of target heating during ion implantation would predict no annealing The implication of this observation for future beam heating calculations is explored briefly

Ion beam excitation of ion-cyclotron waves and ion heating in plasmas with drifting electrons

Abstract: Ion-cyclotron waves are excited by a cesium ion beam in a cesium Q-machine plasma with drifting plasma electrons. These interactions differ significantly from those in the case of drifting ions in that the drifting electrons play an active role in the instability mechanism. The observed mode frequencies are slightly below those of the electron current driven modes. These waves can be convectively or absolutely unstable, depending on the ion beam velocity. For low beam velocities the instabifities are convective in character with large spatial growth rates k i /k r ∼ 0.2. For larger beam velocities the instabilities are absolute in character with temporal growth rates 0.04. The absolute instabilities are similar to two-stream instabilities. Plasma ion heating is observed and is consistent with a model in which mode amplitudes are saturated by diffusion effects.

Effect of preacceleration on intense ion-beam transmission efficiency

Abstract: Utilization of a preacceleration potential to accelerate ions before they reach the emission aperture results in a substantial increase in the transmission efficiency. For an intense modified duoPIGatron focused multibeamlet (1799 apertures) 22‐cm‐diam ion source, the total transmission efficiency for beam power through an aperture 20×25 cm located 4.10 m downstream increased 30%. This result is in agreement with a previous solution to the appropriate two‐dimensional Poisson‐Vlasov equation for ions extracted from a plasma.

Secondary particle collection in ion implantation dose measurement.

Abstract: The measurement of ion implantation doses in the presence of secondary ions and electrons emitted from the target is discussed. A circuit and electrode geometry for obtaining accurate ion beam current measurements in the presence of both positive and negative secondary particles is presented.

Process for channeling ion beams

Abstract: The specification describes a process for minimizing ion scattering and thereby improving resolution in ion beam lithography. First, a substrate coated with a layer of ion beam resist is provided at a chosen spaced distance from an ion beam source. Next, a monocrystalline membrane with a patterned ion absorption region is positioned at a predetermined location between the substrate target and the ion beam source. The patterned ion absorption region may be either an ion absorption mask, such as gold, deposited on the surface of the monocrystalline membrane, or a pattern of ion-damaged regions within the monocrystalline membrane. Finally, a collimated wide area ion beam is passed perpendicular to the surface of the membrane and through crystal lattice channels therein which are exposed by the patterned ion absorption region and which extend perpendicular to the membrane surface. The parallel paths established by the channels in the membrane provide low resistance paths to the passage of ion beams and consequently minimize the angle of deflection of the ions passing from the membrane to the target resist layer.

High temperature ion source for an on-line isotope separator

Abstract: A reduced size ion source for on-line use with a cyclotron heavy-ion beam is provided. A sixfold reduction in source volume while operating with similar input power levels results in a 2000° C. operating temperature. A combined target/window normally provides the reaction products for ionization while isolating the ion source plasma from the cyclotron beam line vacuum. A graphite felt catcher stops the recoiling reaction products and releases them into the plasma through diffusion and evaporation. Other target arrangements are also possible. A twenty-four hour lifetime of unattended operation is achieved, and a wider range of elements can be studied than was heretofore possible.

Low background cold cathode ion source for molecular beam detection.

Abstract: An extractor gauge type electron bombardment ion source using carbon fiber bundles as field electron emitters is described. The cold cathode permits operation of the ionizer within a liquid He cooled cryopump. The high pumping speed for all molecules (except helium) together with its low background pressure make this ion source a very promising detector for crossed molecular beam scattering experiments.

Compound semiconductor wafer

Abstract: A compound semiconductor wafer having a substrate of a IV-group element semiconductor of a predetermined conductivity type, an epitaxial layer formed by epitaxially growing on the substrate a compound semiconductor having the same conductivity type as the substrate by an ion beam deposition process or a cluster ion beam deposition process, and a compound semiconductor layer of a conductivity type opposite to that of the epitaxial layer and formed on the epitaxial layer so as to form a PN junction with the epitaxial layer.

The focusing of an ion beam from a quadrupole mass filter using an electrostatic octopole lens

Abstract: A new very simple method of focusing an ion beam from a quadrupole mass filter has been devised. Using an electrostatic octopole lens it is possible to obtain narrow, high-intensity, low-energy ion beams suitable for use in beam studies of ion-molecule reactions. Only two voltages are necessary to focus the beam unless operating near the space charge limit. It was found that beam intensities and angles are limited only by space charge effects. The system is very much easier to operate than a magnetic sector mass spectrometer and retarding lens, and its performance is equal to and in some respects better than that of the magnetic sector.

Prosthesis, esp. a tooth implantation - using metal substrate coated with biocompatible material providing an interference colour

Abstract: Prosthesis, esp. a tooth implantation, using a substrate (1) made of Ti; a Ti alloy; or steel; and with an interference coloured surface layer (2) of Al2O3, Si3N', or the oxide, nitride, carbice, oxynitride, carbonitride, or boride of another metal which is different to metal (1). The substrate (1) is pref. pretreated, e.g. by etching, electropolishing, or ion-bombardment, prior to applying layer (2), which is pref. achieved by chemical vapour deposition, sputtering, ion beam deposition, or by ion plating. The prosthesis is made of a metal with high strength and elasticity, and is coated with a biocompatible material (2) which prevents reactions or corrosion by liqs. in the body tissue or by friction with the tissue; and coating (2) can be flesh coloured.

Thirty‐centimeter‐diameter ion milling source

Abstract: A 30-cm beam diameter ion source has been designed and fabricated for micromachining and sputtering applications. An argon ion current density of 1 mA/cu cm at 500 eV ion energy was selected as a design operating condition. The completed ion source met the design criteria at this operating condition with a uniform and well-collimated beam having an average variation in current density of + or - 5% over the center of 20 cm of the beam. This ion source has a multipole magnetic field that employs permanent magnets between permeable pole pieces. Langmuir probe surveys of the source plasma support the design concepts of a multipole field and a circumferential cathode to enhance plasma uniformity.

Measurement of Energy Reflection from Metals Bombarded by 10–30 keV Hydrogen Ion Beam

Abstract: Measurement has been made on the energy reflection from Mo, Cu, stainless steel and Al targets bombarded by hydrogen ions in the energy range of 10–30 keV. A broad beam from a duoPIGatron ion source is applied on a large target plate and the reflected energy flux is received by a small thermocouple. The results are compared with theoretical calculations and experimental data reported in literature.

Hole Geometry Optimization of the Extraction Electrode in a Duopigatron Ion Source

Abstract: The optimum shape of the extraction aperture in the positive electrode is investigated experimentally by using a duopigatron ion source with single hole extraction electrodes. We find that a slightly chamfered aperture gives the best beam divergence without decreasing the optimum perveance. This result is applied to the ion sources of the JFT-2 neutral beam injector and the injection power to the torus can be improved appreciably. The computational result about the optimum emitting surface by the ion beam simulation code indicates that a slight chamfering is preferable for beam optics.

Ion beam deposition

Abstract: PURPOSE:For ion beam deposition of nonconducting material, a part of ion beam is collided with the inner face of the barrier to produce secondary electrons, both of the ions and electrons being projected onto the target to be neutralized there by exchanging electric charges. CONSTITUTION:A plasma 2 is formed by electron bombardment or the like in the chamber 1 filled with vapor to be deposited at a specified pressure. A high negative voltage is applied to the extracting electrode 5 which extends from the positive ion port 3 into the process chamber 4 to draw ion beam into the chamber 4. A part of the ion beam 6 is hit against the internal wall of the current pass barrier 7 having holes, producing electrons. The emitted secondary electrons and ion beams 8 are collided to the target 9 and neutralized while forming the deposited material 10. The applying voltage to the barrier plate 7 is limited by the ion collosion. Therefore, it must be lower that the potential of the plasma 2. About the same voltage as the draw voltage of the ion 6 is sufficient.