DOCSLIB.ORG

Study of Plasma and Ion Beam Sputtering Processes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text

Load more

Journal of Physical Science and Application 5 (2) (2015) 128-142 doi: 10.17265/2159-5348/2015.02.007 D DAVID PUBLISHING Study of Plasma and Ion Beam Sputtering Processes M.M.Abdelrahman Accelerators and Ion Sources Department, Nuclear Research Center, Atomic Energy Authority, 13759 Inchas, Atomic Energy, Cairo, Egypt Abstract: The effects of plasma (ions, electrons) and other energetic particles are now widely used for substrate cleaning as well as to assist and control thin film growth and various applications. In this work, historical review of the plasma and its various types are given and described. Different types of gas discharge and plasma production are also discussed in detail. Furthermore, technique of ion beam extraction from a plasma source for sputtering process by using a suitable electrode is carefully studied and given. In further consequence, a general review about the physics and mechanism of sputtering processes is studied. Different types of sputtering techniques are investigated and clarified. Theoretical treatment for determination of sputtering yield for low and high atomic species elements as a function of energy from 100 to 5,000 eV are studied and discussed. Finally, various applications of plasma-and-ion beam sputtering will also be mentioned and discussed. Key words: Plasma, ion sputtering, gas mixing, electron injection. 1. Introduction multicharged ions was given a strong input by studies in connection with fusion research, to deepen our The plasma is the fourth state of the matter, fundamental understanding of the mechanisms of the following the solid, liquid and gaseous states. As the involved collision processes. Accurate knowledge of temperature of the substance increased, the material total electron capture cross sections helps in changes firstly from solid to liquid, then liquid to gas explaining and solving problems in the field of fusion and finally from gas to plasma [1]. In general, there research, astrophysics and laboratory plasma. The are three different kinds of these individual particles more demanding the applications of the plasma that make up the plasma, they are ions, electrons and sources, the more the plasma source has to be neutral particles. Plasma exists in nature as in the sun, carefully designed and optimised to get optimum stars and in the ionosphere and on the earth in performance. High performance of plasma sources transient forms such as lighting. Man made plasmas represents in having ionization efficiency, maximum such as fluorescent lamps, neon signs and high voltage current, high charge state, size and cost taking into sparks industrially, plasmas are used in various forms account the limits of power and the radiation as in semi-conductor processing, material environment. In general, the plasma (ion) source is the modifications and synthesis and other purposes. The main component of any accelerator, from which development of PS (plasma sources) received a strong originates the beam of ions or electrons. Hence, its push from plasma centers all over the world, due to specifications should be carefully considered to adapt the fact that the advancement range of these sources is the expected application. In its basic operation (for strongly increased by the charge state of the plasma ions), a gas is ionized, usually by subjecting it to an sources. Moreover, the plasma sources are useful for electric discharge, and the positively charged ions are basic investigations in atomic physics, surface physics extracted by acceleration towards a negative electrode and related areas. The low energy atomic physics with at a potential of negative potential. The characteristics of the ion source determine to a great extent the Corresponding author: M.M.Abdelrahman. E-mail: [email protected]. performance of the accelerating system. The selection Study of Plasma and Ion Beam Sputtering Processes 129 of an ion source for a particular application should be kind or another. Industrially, plasmas are used in made with due consideration of factors such as species various forms for semiconductor processing, lighting, and intensity capability, beam quality (emittance and materials modification and synthesis and other brightness), ionization efficiency, reliability ,ease of purposes. operation, maintenance, and source lifetime. No truly 1.2 Applications of Plasma Sources universal source exists that will meet all applications requirements. In this work, historical review of the Applications of plasma sources from providing plasma and its various types are given and described. beams of hundreds of amperes for fusion, Different types of gas discharge and plasma nano-amperes for microprobe trace analysis, broad production are also discussed in detail. Furthermore, beams for ion implantation, space thrusters, industrial technique of ion beam extraction from a plasma polymerisation, food sterilisation, to medical, military source for sputtering process by using a suitable and accelerator applications. PIG ion sources have electrode is carefully studied and given. In a found widespread applications in the injectors of the furthermore consequence, a general review about the large particle accelerators used for nuclear and physics and mechanism of sputtering processes is high-energy physics research. The Freeman ion source studied. Different types of sputtering techniques are is widely used in the commercially available ion investigated and clarified. Theoretical treatment for implantation equipment. Laser ion sources, where determination of sputtering yield with low and high very high energy fluxes that can be delivered onto atomic species elements as a function of incident solid targets using a high power pulsed laser can be energy from 100 to 5000 ev are studied. Finally, used to produce dense pulsed plasma with a high various applications of plasma-and-ion beam fraction of highly stripped ion species. In the EBIS sputtering will also be mentioned and discussed. (electron beam ion source), the ions are contained within a high-energy electron beam in a strong 1.1 General Considerations on Plasma Sources magnetic field and in a very high vacuum, for a Plasma is resulted from ionization of neutral gases sufficiently long time for very high charge state ions generally equal numbers of positive and negative to be produced. This ion source is particularly suitable charge carriers. Such plasma is characterized by for particle accelerator injection, especially heavy ion quasi-neutral. When blood is cleared of its various synchrotrons as well as to basic atomic physics. ECR constituents, there remains a transparent liquid which ion sources have the advantage for using as high was named plasma (gely). By comparison to this charge state ion injectors for nuclear physics, particle definition, Irving Langmuir [2] first used this term accelerators especially cyclotrons. Microwave ion “plasma” in 1927 and won Noble prize for this sources used for the filamentless production of high discovery. Plasmas exist in nature in those current beams for high dose ion implantation into environments where the temperature is adequately semiconductors. The excellent performance of the high, such as in the sun, stars and in the ionosphere Freeman ion source is the ion implantation and and on the earth in transient forms such as lighting. industrial applications, especially for semiconductor Man-made plasmas have become commonplace and purposes. Penning ion sources are found to be more are part of the modern world in forms such as successful than other sources for many types of fluorescent lamps, neon signs and high voltage sparks. accelerators. RF ion sources have been used in plasma Laboratory plasmas can be created in a wide variety of and reactive ion beam etching and ion beam doping. ways, most commonly as electrical discharges of one Also, they are widely employed by the semiconductor 130 Study of Plasma and Ion Beam Sputtering Processes industry. Today, ion sources are considered the main the source lifetime, the source size, the power component of the particle accelerator system. Particle efficiency and the ease of maintenance. Fig. 2 accelerators are widely used in nearly every field of illustrates the main parameters for different types of physics from elementary particles to solid state ion sources. physics. They also considered an essential part in 1.4 Gas Discharge Processes many other areas of researches as chemistry, biology, etc (Fig. 1) [3]. Industrial applications cover a wide Ionization is a process in which an atom loses one range as ion implantation in the semiconductor or more of its electrons to another atom. The process industry, indeed, the modification of surface of ionization occurs in nature as a result of properties of many materials. Applications of interactions of photons, electrons, or ions with matter. accelerators in medicine have found wide areas as The most essential setup in every ionization process is isotope production in view diagnostics or treatment, or for therapy with gamma rays and more recently, with neutrons and heavy charged particles. 1.3 Main Parameters of Plasma Sources Different applications of plasma sources require somewhat different sets of certain performance characteristics. Ion sources are characterized by the following parameters [4]: (1) The type of ion species that can be produced by the source. (2) The ability of producing ions of different elements for their applications in particle accelerators, atomic physics, etc. (3) The extracted ion current. (4) The
Recommended publications
  • UHV Thin Film Sputter Deposition System James Joshua Street May

    UHV Thin Film Sputter Deposition System James Joshua Street May

    UHV Thin Film Sputter Deposition System James Joshua Street May 2008 Introduction Thin-film deposition is any technique for depositing a thin film of material onto a substrate. It is useful in manufacturing optics, electronics (semiconductors), coatings (such as wear or corrosion resistance), and various composite materials. Thin film creation can be accomplished using a variety of different methods. The vast majority of these methods can be categorized into two regimes: chemical vapor deposition and physical vapor deposition. A substrate is exposed to various volatile precursor gases that react or decompose onto the substrate during chemical vapor deposition. On the other hand, physical deposition methods work by sputtering or evaporating the material, creating a gaseous plume that deposits a film onto the substrate. Within an evaporative mechanism, the source material is heated until it evaporates and condenses on the substrate. Evaporation must occur in a vacuum, so that the mean free path will be large enough that the particles can travel directly to the substrate without colliding with the background gas molecules. Thermal methods to promote evaporation include radiative heating, resistive heating, electron-beam heating, and pulse-laser systems of suitable sources (“Thin Film Deposition Technical Notes,” 2007). I aided in the closing of a ultra-high vacuum (UHV) sputter deposition system, which is a method of coating a substrate using material that is removed from a solid target by energetic ion bombardment. This process needs to be done in UHV in order to prevent contaminants and to allow sputtered particles to travel far enough to be deposited onto the substrate.
  • Conceptual Design for a Sputter-Type Negative Ion Source Based

    Conceptual Design for a Sputter-Type Negative Ion Source Based

    MOPO-03 Proceedings of ECRIS08, Chicago, IL USA CONCEPTUAL DESIGN OF A SPUTTER-TYPE NEGATIVE ION SOURCE BASED ON ELECTRON CYCLOTRON RESONANCE PLASMA HEATING O. Tarvainen and S. Kurennoy, Los Alamos National Laboratory, Los Alamos, NM 87545, U.S.A. Abstract PHYSICS ASPECTS OF H- ION BEAM A design for a negative ion source based on electron PRODUCTION cyclotron resonance plasma heating and ionization by Modern H- ion sources are based on two important ion surface sputtering is presented. The plasma chamber of formation processes, the volume [3] and the surface [4] the source is an rf-cavity designed for TE111 eigenmode at production. The relative importance of these processes 2.45 GHz. The desired mode is excited with a loop depends on the detailed design of the ion source. antenna. The ionization process takes place on a cesiated The volume production of H- is generally accepted to surface of a biased converter electrode (cathode). The ion be due to dissociative attachment (DA) of low energy beam is further “self-extracted” through the plasma electrons to rovibrationally (ν,,) excited molecules. Two region. The magnetic field of the source is optimized for electron populations are needed in order to optimize the both, plasma generation by electron cyclotron resonance volume production process: hot electrons (few eV) heating, and beam extraction. The source can be used for creating the excited molecular states i.e. ehot + H2 Æ e + a production of a variety of negative ions ranging from v’’ H2 (v’’ > 5) and cold electrons (less than 1 eV) hydrogen to heavy ions.
  • Sputter-Deposited Titanium Oxide Layers As Efficient Electron Selective Contacts in Organic Photovoltaic Devices

    Sputter-Deposited Titanium Oxide Layers As Efficient Electron Selective Contacts in Organic Photovoltaic Devices

    Sputter-Deposited Titanium Oxide Layers as Efficient Electron Selective Contacts in Organic Photovoltaic Devices Mina Mirsafaei, Pia Bomholt Jensen, Mehrad Ahmadpour, Harish Lakhotiya, John Lundsgaard Hansen, Brian Julsgaard, Horst-Günter Rubahn, Remi Lazzari, Nadine Witkowski, Peter Balling, et al. To cite this version: Mina Mirsafaei, Pia Bomholt Jensen, Mehrad Ahmadpour, Harish Lakhotiya, John Lundsgaard Hansen, et al.. Sputter-Deposited Titanium Oxide Layers as Efficient Electron Selective Contacts in Organic Photovoltaic Devices. ACS Applied Energy Materials, ACS, 2019, 3 (1), pp.253-259. 10.1021/acsaem.9b01454. hal-02995171 HAL Id: hal-02995171 https://hal.archives-ouvertes.fr/hal-02995171 Submitted on 2 Dec 2020 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Sputter deposited titanium oxide layers as efficient electron selective contacts in organic photovoltaic devices Mina Mirsafaei1, Pia Bomholt Jensen2, Mehrad Ahmadpour1, Harish Lakhotiya2, John Lundsgaard Hansen2, Brian Julsgaard2, Horst-Günter Rubahn1, Rémi Lazzari3, Nadine Witkowski3, Peter Balling2, Morten Madsen1* 1 SDU NanoSYD, Mads Clausen Institute, University of Southern Denmark, Alsion 2, Sønderborg, DK-6400, Denmark 2 Department of Physics and Astronomy/Interdisciplinary Nanoscience Center (iNano), Aarhus University, Ny Munkegade 120, DK-8000 Aarhus C, Denmark 3 Sorbonne Université, UMR CNRS 7588, Institut des Nanosciences de Paris (INSP), 4 place Jussieu, 75005 Paris, France KEYWORDS.
  • Sputter Coating Technical Brief

    Sputter Coating Technical Brief

    Sputter Coating Technical Brief Document Number TB-SPUTTER Issue 2 (01/02) Introduction HP000107 Quorum Technologies Ltd main sales office: South Stour Avenue Ashford Kent U.K. Tel: ++44(0) 1233 646332 TN23 7RS Fax: ++44(0) 1233 640744 Email: [email protected] http:///www.quorumtech.com For further information regarding any of the other products designed and manufactured by Quorum Technologies, contact your local representative or directly to Quorum Technologies at the address above. Carbon and sputter coaters Plasma reactor for ashing and etching High vacuum bench top evaporators Cryo-SEM preparation systems Critical point dryers Freeze dryers for electron microscopy Service and Spares Disclaimer The components and packages described in this document are mutually compatible and guaranteed to meet or exceed the published performance specifications. No performance guarantees, however, can be given in circumstances where these component packages are used in conjunction with equipment supplied by companies other than Quorum Technologies. Quorum Technologies Limited, Company No. 04273003 Registered office: Unit 19, Charlwoods Road, East Grinstead, West Sussex, RH19 2HL, UK TB-SPUTTER Contents Contents Chapter 1 - Introduction .......................................................................................... 4 Chapter 2 - Gaseous Condition .............................................................................. 5 Chapter 3 - Glow Discharge ...................................................................................
  • A Self-Sputtering Ion Source: a New Approach to Quiescent Metal Ion Beams

    A Self-Sputtering Ion Source: a New Approach to Quiescent Metal Ion Beams

    Lawrence Berkeley National Laboratory Lawrence Berkeley National Laboratory Title A self-sputtering ion source: A new approach to quiescent metal ion beams Permalink https://escholarship.org/uc/item/24w7z1p2 Author Oks, Efim M. Publication Date 2010-03-31 Peer reviewed eScholarship.org Powered by the California Digital Library University of California Presented at the International Conference on Ion Sources on September 24, 2009 and submitted for publication to Review of Scientific Instruments received September 3, 2009, accepted November 13, 2009 A self-sputtering ion source: A new approach to quiescent metal ion beams Efim Oks1 and André Anders2* 1High Current Electronics Institute, Russian Academy of Sciences, 2/3 Academichesky Ave., Tomsk 634055, Russia 2Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA *corresponding author, email [email protected] rev. version of November 05, 2009 ACKNOWLEDGMENT The work was supported by the US Department of Energy under Contract No DE-AC02-05CH11231 with the Lawrence Berkeley National Laboratory. DISCLAIMER This document was prepared as an account of work sponsored in part by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the University of California, nor any of their employees, makes any warranty, express or implied, or assumes any legal responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by its trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof, or The Regents of the University of California.
  • Composition and Properties of RF-Sputter Deposited Titanium Dioxide Thin Films

    Composition and Properties of RF-Sputter Deposited Titanium Dioxide Thin Films

    Nanoscale Advances PAPER View Article Online View Journal | View Issue Composition and properties of RF-sputter deposited titanium dioxide thin films† Cite this: Nanoscale Adv.,2021,3,1077 Jesse Daughtry, ab Abdulrahman S. Alotabi,ab Liam Howard-Fabrettoab and Gunther G. Andersson *ab The photocatalytic properties of titania (TiO2) have prompted research utilising its useful ability to convert solar energy into electron–hole pairs to drive novel chemistry. The aim of the present work is to examine the properties required for a synthetic method capable of producing thin TiO2 films, with well defined, easily modifiable characteristics. Presented here is a method of synthesis of TiO2 nanoparticulate thin films generated using RF plasma capable of homogenous depositions with known elemental composition and modifiable properties at a far lower cost than single-crystal TiO2. Multiple depositions regimes were Received 14th October 2020 examined for their effect on overall chemical composition and to minimise the unwanted contaminant, Accepted 7th December 2020 carbon, from the final film. The resulting TiO2 films can be easily modified through heating to further DOI: 10.1039/d0na00861c induce defects and change the electronic structure, crystallinity, surface morphology and roughness of Creative Commons Attribution-NonCommercial 3.0 Unported Licence. rsc.li/nanoscale-advances the deposited thin film. Introduction nanoparticulate TiO2. Nanoparticle Titania has shown partic- ular promise across the range of possible applications and also ff Titania (TiO2)
  • Tracing the Recorded History of Thin-Film Sputter Deposition: from the 1800S to 2017

    Tracing the Recorded History of Thin-Film Sputter Deposition: from the 1800S to 2017

    Review Article: Tracing the recorded history of thin-film sputter deposition: From the 1800s to 2017 Cite as: J. Vac. Sci. Technol. A 35, 05C204 (2017); https://doi.org/10.1116/1.4998940 Submitted: 24 March 2017 . Accepted: 10 May 2017 . Published Online: 08 September 2017 J. E. Greene COLLECTIONS This paper was selected as Featured ARTICLES YOU MAY BE INTERESTED IN Review Article: Plasma–surface interactions at the atomic scale for patterning metals Journal of Vacuum Science & Technology A 35, 05C203 (2017); https:// doi.org/10.1116/1.4993602 Microstructural evolution during film growth Journal of Vacuum Science & Technology A 21, S117 (2003); https://doi.org/10.1116/1.1601610 Overview of atomic layer etching in the semiconductor industry Journal of Vacuum Science & Technology A 33, 020802 (2015); https:// doi.org/10.1116/1.4913379 J. Vac. Sci. Technol. A 35, 05C204 (2017); https://doi.org/10.1116/1.4998940 35, 05C204 © 2017 Author(s). REVIEW ARTICLE Review Article: Tracing the recorded history of thin-film sputter deposition: From the 1800s to 2017 J. E. Greenea) D. B. Willett Professor of Materials Science and Physics, University of Illinois, Urbana, Illinois, 61801; Tage Erlander Professor of Physics, Linkoping€ University, Linkoping,€ Sweden, 58183, Sweden; and University Professor of Materials Science, National Taiwan University Science and Technology, Taipei City, 106, Taiwan (Received 24 March 2017; accepted 10 May 2017; published 8 September 2017) Thin films, ubiquitous in today’s world, have a documented history of more than 5000 years. However, thin-film growth by sputter deposition, which required the development of vacuum pumps and electrical power in the 1600s and the 1700s, is a much more recent phenomenon.
  • Deposition and Characterization of Magnetron Sputtered Beta

    Deposition and Characterization of Magnetron Sputtered Beta

    Deposition and Characterization of Magnetron Sputtered Beta-Tungsten Thin Films Jiaxing Liu Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2016 © 2016 Jiaxing Liu All Rights Reserved ABSTRACT Deposition and Characterization of Magnetron Sputtered Beta-Tungsten Thin Films Jiaxing Liu β-W is an A15 structured phase commonly found in tungsten thin films together with the bcc structured W, and it has been found that β-W has the strongest spin Hall effect among all metal thin films. Therefore, it is promising for application in spintronics as the source of spin- polarized current that can be easily manipulated by electric field. However, the deposition conditions and the formation mechanism of β-W in thin films are not fully understood. The existing deposition conditions for β-W make use of low deposition rate, high inert gas pressure, substrate bias, or oxygen impurity to stabilize the β-W over α-W, and these parameters are unfavorable for producing β-W films with high quality at reasonable yield. In order to optimize the deposition process and gain insight into the formation mechanism of β-W, a novel technique using nitrogen impurity in the pressure range of 10-5 to 10-6 torr in the deposition chamber is introduced. This techniques allows the deposition of pure β-W thin films with only incorporation of 0.4 at% nitrogen and 3.2 at% oxygen, and β-W films as thick as 1μm have been obtained. The dependence of the volume fraction of β-W on the deposition parameters, including nitrogen pressure, substrate temperature, and deposition rate, has been investigated.
  • Molecular Ion Sources for Low Energy Semiconductor Ion Implantation

    Molecular Ion Sources for Low Energy Semiconductor Ion Implantation

    BNL-112215-2016-CP Molecular ion sources for low energy semiconductor ion implantation 1 2 3 A. I. Hershcovitch , V. I. Gushenets , D. N. Seleznev , 2 4 2 3 B. A. S. Bugaev , S. Dugin , E. M. Oks , T. V. Kulevoy , 4 3 3 C. O. Alexeyenko , A. Kozlov , G. N. Kropachev , 3 3 2 2 D. R. P. Kuibeda , S. Minaev , A. Vizir , G. Y. Yushkov 1Brookhaven National Laboratory, Upton, NY 11973 USA 2High Current Electronics Institute, Siberian Branch of Russian Academy of Sciences, Tomsk 634055 Russia 3Institute for Theoretical and Experimental Physics, Moscow 117218 Russia 4State Scientific Center of the Russian Federation State Research Institute for Chemistry and Technology of Organoelement Compounds, Moscow Russia Presented at the 16th International Conference on Ion Sources New York Marriott Marquis Hotel, New York, NY August 23 – 28, 2015 May 2016 Collider-Accelerator Department Brookhaven National Laboratory U.S. Department of Energy Office of Science, Office of Nuclear Physics Notice: This manuscript has been authored by employees of Brookhaven Science Associates, LLC under Contract No. DE-SC0012704 with the U.S. Department of Energy. The publisher by accepting the manuscript for publication acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, nor any of their contractors, subcontractors, or their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or any third party’s use or the results of such use of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights.
  • Deposition Lecture Day 2 Deposition

    Deposition Lecture Day 2 Deposition

    Deposition Lecture Day 2 Deposition PVD - Physical Vapor Deposition E-beam Evaporation Thermal Evaporation (wire feed vs boat) Sputtering CVD - Chemical Vapor Deposition PECVD LPCVD MVD ALD MBE Plating Parylene Coating Vacuum Systems, pumps and support equipment Differences, Pros and Cons for depositing various materials Physical vs. Chemical Deposition Metallization - depositing metal layers or thin films - E-beam & Thermal Evaporation, Sputtering, Plating - Contact layer, mask/protection layer, interface layers Dielectric Deposition - depositing dielectric layers or thin films -CVD, e-beam, sputtering - insulating/capacitor layer, mask/protecting layer, interface layers *Dielectric = an electrical insulator that can be polarized by an applied electric field. ~energy storing capacity → capacitor Environment of the Deposition *Cleanroom is not enough! Must also be in vacuum! Purity of the deposited film depends on the quality of the vacuum, and on the purity of the source material. Cryo pumps Evaporation is a common method of thin-film deposition. The source material is evaporated in a vacuum. The vacuum allows vapor particles to travel directly to the target object (substrate), where they condense back to a solid state. Evaporation is used in microfabrication, and to make macro-scale products such as metallized plastic film. Any evaporation system includes a vacuum pump. It also includes an energy source that evaporates the material to be deposited. Many different energy sources exist: ● In the thermal method, metal material (in the form of wire, pellets, shot) is fed onto heated semimetal (ceramic) evaporators known as "boats" due to their shape. A pool of melted metal forms in the boat cavity and evaporates into a cloud above the source.
  • Mini RF-Driven Ion Source for Focused Ion Beam System

    Mini RF-Driven Ion Source for Focused Ion Beam System

    Mini RF-driven ion sources for focused ion beam systems X. Jiang a), Q. Ji, A. Chang, and K. N. Leung. Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 Abstract Mini RF-driven ion sources with 1.2 cm and 1.5 cm inner chamber diameter have been developed at Lawrence Berkeley National Laboratory. Several gas species have been tested including argon, krypton and hydrogen. These mini ion sources operate in inductively coupled mode and are capable of generating high current density ion beams at tens of watts. Since the plasma potential is relatively low in the plasma chamber, these mini ion sources can function reliably without any perceptible sputtering damage. The mini RF-driven ion sources will be combined with ele ctrostatic focusing columns, and are capable of producing nano focused ion beams for micro machining and semiconductor fabrications. INTRODUCTION: Recently focused ion beam (FIB) systems have been used for circuit inspection, mask repair, micro machining, ion doping, and direct resistless writing. Most FIB systems employ a liquid metal ion source (LMIS). LMIS has a very low current yield and very high angular divergence. The gallium ion generated by liquid metal ion source can cause contamination in many FIB applications. For example, when LMIS is used for sputtering of copper, a Cu3Ga phase alloy can be formed, which is particularly resistant to milling and contributes to the uneven profiles [1]. L. Scipioni and coworkers[2] have demonstrated that when gallium ion beam is used for photo mask repair, implanted gallium ions can absorb 73% of incident 248 and 193 nm ultraviolet light.
  • General Disclaimer One Or More of the Following Statements May Affect This Document

    General Disclaimer One Or More of the Following Statements May Affect This Document

    General Disclaimer One or more of the Following Statements may affect this Document This document has been reproduced from the best copy furnished by the organizational source. It is being released in the interest of making available as much information as possible. This document may contain data, which exceeds the sheet parameters. It was furnished in this condition by the organizational source and is the best copy available. This document may contain tone-on-tone or color graphs, charts and/or pictures, which have been reproduced in black and white. This document is paginated as submitted by the original source. Portions of this document are not fully legible due to the historical nature of some of the material. However, it is the best reproduction available from the original submission. Produced by the NASA Center for Aerospace Information (CASI) i NASA TECHNICAL NASA TM X-73511 MEMORANDUM M ti X ^e B 91n17j,, un z On NONPROPULSIVE APPLICATIONS OF ION BEAMS by W. R. Hudson Lewis Research Center Cleveland. Ohio 44135 TECHNICAL PAPER to be presented at the Twelfth International Electric Propulsion Conference sponsored by the American Institute of Ae ronautics and Astronautics Key Bisca}, ne, Florida. November 15-17, 1976 (NASA-TM-X-73511) NONPROPULSIVF N77-12847 APPLICATIONS OF ION BEAM) (NASA) 16 p HC A02/MF A01 CSCL 20J Unclas 63/73 56895 } i NONPROPULSIVE APPLICATIONS OF ION BEAMS W. R. Hudson Natiunal Aeionautica and Space Administration Lewis Research Center Cleveland, Ohio 44135 Abstract terial, which is then deposited onto a substrate. In ion beam machining (fig, lb) a maks is placed This paper describes the results of an inves- between the source and the target, such that target tigation of the nonpropulsive applications of elec- material is selectively removed from the unahlelded tric propulaion technology.