Characterisation of the beam plasma in high current, low energy ion beams for implanters

J. Fiala, D. G. Armour, J. A. Van Den Berg, A. J.T. Holmes, R. D. Goldberg, E. H.J. Collart

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

The effective transport of high current, positive ion beams at low energies in ion implanters requires the a high level of space charge compensation. The self-induced or forced introduction of electrons is known to result in the creation of a so-called beam plasma through which the beam propagates. Despite the ability of beams at energies above about 3-5 keV to create their own neutralising plasmas and the development of highly effective, plasma based neutralising systems for low energy beams, very little is known about the nature of beam plasmas and how their characteristics and capabilities depend on beam current, beam energy and beamline pressure. These issues have been addressed in a detailed scanning Langmuir probe study of the plasmas created in beams passing through the post-analysis section of a commercial, high current ion implanter. Combined with Faraday cup measurements of the rate of loss of beam current in the same region due to charge exchange and scattering collisions, the probe data have provided a valuable insight into the nature of the slow ion and electron production and loss processes. Two distinct electron energy distribution functions are observed with electron temperatures ≥ 25 V and around 1 eV. The fast electrons observed must be produced in their energetic state. By studying the properties of the beam plasma as a function of the beam and beamline parameters, information on the ways in which the plasma and the beam interact to reduce beam blow-up and retain a stable plasma has been obtained.

LanguageEnglish
Title of host publicationIon Impantation Technology
Subtitle of host publication16th International Conference on Ion Implantation Technology, IIT 2006
EditorsKaren Kirkby, Russell Gwilliam, Andy Smith, David Chivers
PublisherAmerican Institute of Physics Publising LLC
Pages340-344
Number of pages5
Volume866
ISBN (Print)9780735403659
Publication statusPublished - 28 Dec 2006
Externally publishedYes
EventION IMPLANTATION TECHNOLOGY: 16th International Conference on Ion Implantation Technology, IIT 2006 - Marseille, France
Duration: 11 Jun 200616 Nov 2006

Conference

ConferenceION IMPLANTATION TECHNOLOGY: 16th International Conference on Ion Implantation Technology, IIT 2006
CountryFrance
CityMarseille
Period11/06/0616/11/06

Fingerprint

high current
ion beams
energy
beam currents
electron energy
ions
electrons
electrostatic probes
positive ions
charge exchange
space charge
energy distribution
distribution functions
collisions
scanning
probes
scattering

Cite this

Fiala, J., Armour, D. G., Van Den Berg, J. A., Holmes, A. J. T., Goldberg, R. D., & Collart, E. H. J. (2006). Characterisation of the beam plasma in high current, low energy ion beams for implanters. In K. Kirkby, R. Gwilliam, A. Smith, & D. Chivers (Eds.), Ion Impantation Technology: 16th International Conference on Ion Implantation Technology, IIT 2006 (Vol. 866, pp. 340-344). American Institute of Physics Publising LLC.
Fiala, J. ; Armour, D. G. ; Van Den Berg, J. A. ; Holmes, A. J.T. ; Goldberg, R. D. ; Collart, E. H.J. / Characterisation of the beam plasma in high current, low energy ion beams for implanters. Ion Impantation Technology: 16th International Conference on Ion Implantation Technology, IIT 2006. editor / Karen Kirkby ; Russell Gwilliam ; Andy Smith ; David Chivers. Vol. 866 American Institute of Physics Publising LLC, 2006. pp. 340-344
@inproceedings{ef2c05f805ce4fb7aa7420ac69ff974f,
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abstract = "The effective transport of high current, positive ion beams at low energies in ion implanters requires the a high level of space charge compensation. The self-induced or forced introduction of electrons is known to result in the creation of a so-called beam plasma through which the beam propagates. Despite the ability of beams at energies above about 3-5 keV to create their own neutralising plasmas and the development of highly effective, plasma based neutralising systems for low energy beams, very little is known about the nature of beam plasmas and how their characteristics and capabilities depend on beam current, beam energy and beamline pressure. These issues have been addressed in a detailed scanning Langmuir probe study of the plasmas created in beams passing through the post-analysis section of a commercial, high current ion implanter. Combined with Faraday cup measurements of the rate of loss of beam current in the same region due to charge exchange and scattering collisions, the probe data have provided a valuable insight into the nature of the slow ion and electron production and loss processes. Two distinct electron energy distribution functions are observed with electron temperatures ≥ 25 V and around 1 eV. The fast electrons observed must be produced in their energetic state. By studying the properties of the beam plasma as a function of the beam and beamline parameters, information on the ways in which the plasma and the beam interact to reduce beam blow-up and retain a stable plasma has been obtained.",
keywords = "Ion implanter, Langmuir probe, Low energy beam transport",
author = "J. Fiala and Armour, {D. G.} and {Van Den Berg}, {J. A.} and Holmes, {A. J.T.} and Goldberg, {R. D.} and Collart, {E. H.J.}",
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}

Fiala, J, Armour, DG, Van Den Berg, JA, Holmes, AJT, Goldberg, RD & Collart, EHJ 2006, Characterisation of the beam plasma in high current, low energy ion beams for implanters. in K Kirkby, R Gwilliam, A Smith & D Chivers (eds), Ion Impantation Technology: 16th International Conference on Ion Implantation Technology, IIT 2006. vol. 866, American Institute of Physics Publising LLC, pp. 340-344, ION IMPLANTATION TECHNOLOGY: 16th International Conference on Ion Implantation Technology, IIT 2006, Marseille, France, 11/06/06.

Characterisation of the beam plasma in high current, low energy ion beams for implanters. / Fiala, J.; Armour, D. G.; Van Den Berg, J. A.; Holmes, A. J.T.; Goldberg, R. D.; Collart, E. H.J.

Ion Impantation Technology: 16th International Conference on Ion Implantation Technology, IIT 2006. ed. / Karen Kirkby; Russell Gwilliam; Andy Smith; David Chivers. Vol. 866 American Institute of Physics Publising LLC, 2006. p. 340-344.

Research output: Chapter in Book/Report/Conference proceedingConference contribution

TY - GEN

T1 - Characterisation of the beam plasma in high current, low energy ion beams for implanters

AU - Fiala, J.

AU - Armour, D. G.

AU - Van Den Berg, J. A.

AU - Holmes, A. J.T.

AU - Goldberg, R. D.

AU - Collart, E. H.J.

PY - 2006/12/28

Y1 - 2006/12/28

N2 - The effective transport of high current, positive ion beams at low energies in ion implanters requires the a high level of space charge compensation. The self-induced or forced introduction of electrons is known to result in the creation of a so-called beam plasma through which the beam propagates. Despite the ability of beams at energies above about 3-5 keV to create their own neutralising plasmas and the development of highly effective, plasma based neutralising systems for low energy beams, very little is known about the nature of beam plasmas and how their characteristics and capabilities depend on beam current, beam energy and beamline pressure. These issues have been addressed in a detailed scanning Langmuir probe study of the plasmas created in beams passing through the post-analysis section of a commercial, high current ion implanter. Combined with Faraday cup measurements of the rate of loss of beam current in the same region due to charge exchange and scattering collisions, the probe data have provided a valuable insight into the nature of the slow ion and electron production and loss processes. Two distinct electron energy distribution functions are observed with electron temperatures ≥ 25 V and around 1 eV. The fast electrons observed must be produced in their energetic state. By studying the properties of the beam plasma as a function of the beam and beamline parameters, information on the ways in which the plasma and the beam interact to reduce beam blow-up and retain a stable plasma has been obtained.

AB - The effective transport of high current, positive ion beams at low energies in ion implanters requires the a high level of space charge compensation. The self-induced or forced introduction of electrons is known to result in the creation of a so-called beam plasma through which the beam propagates. Despite the ability of beams at energies above about 3-5 keV to create their own neutralising plasmas and the development of highly effective, plasma based neutralising systems for low energy beams, very little is known about the nature of beam plasmas and how their characteristics and capabilities depend on beam current, beam energy and beamline pressure. These issues have been addressed in a detailed scanning Langmuir probe study of the plasmas created in beams passing through the post-analysis section of a commercial, high current ion implanter. Combined with Faraday cup measurements of the rate of loss of beam current in the same region due to charge exchange and scattering collisions, the probe data have provided a valuable insight into the nature of the slow ion and electron production and loss processes. Two distinct electron energy distribution functions are observed with electron temperatures ≥ 25 V and around 1 eV. The fast electrons observed must be produced in their energetic state. By studying the properties of the beam plasma as a function of the beam and beamline parameters, information on the ways in which the plasma and the beam interact to reduce beam blow-up and retain a stable plasma has been obtained.

KW - Ion implanter

KW - Langmuir probe

KW - Low energy beam transport

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M3 - Conference contribution

SN - 9780735403659

VL - 866

SP - 340

EP - 344

BT - Ion Impantation Technology

A2 - Kirkby, Karen

A2 - Gwilliam, Russell

A2 - Smith, Andy

A2 - Chivers, David

PB - American Institute of Physics Publising LLC

ER -

Fiala J, Armour DG, Van Den Berg JA, Holmes AJT, Goldberg RD, Collart EHJ. Characterisation of the beam plasma in high current, low energy ion beams for implanters. In Kirkby K, Gwilliam R, Smith A, Chivers D, editors, Ion Impantation Technology: 16th International Conference on Ion Implantation Technology, IIT 2006. Vol. 866. American Institute of Physics Publising LLC. 2006. p. 340-344