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Superconducting Magnet Electron Cyclotron Resonance Ion Source

IP.com Disclosure Number: IPCOM000108290D
Original Publication Date: 1992-May-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 1 page(s) / 48K

Publishing Venue

IBM

Related People

Cuomo, JJ: AUTHOR [+2]

Abstract

Electron cyclotron plasmas have become increasingly valuable for thin film processing due to the high plasma currents obtained (*). The use of Electron Cyclotron Resonance (ECR) plasmas is restricted by the difficulty in obtaining high magnetic fields, typically over 1000 Gauss, over a large volume. Due to poor quality, conventional magnetic field coils, the magnetic field is generally weak, divergent, and results in poor ion confinement. In addition, the increased heat load caused by conventional electromagnets adds to the already high thermal load on the chamber, resulting in increased chamber heating.

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Superconducting Magnet Electron Cyclotron Resonance Ion Source

       Electron cyclotron plasmas have become increasingly
valuable for thin film processing due to the high plasma currents
obtained (*).  The use of Electron Cyclotron Resonance (ECR) plasmas
is restricted by the difficulty in obtaining high magnetic fields,
typically over 1000 Gauss, over a large volume.  Due to poor quality,
conventional magnetic field coils, the magnetic field is generally
weak, divergent, and results in poor ion confinement.  In addition,
the increased heat load caused by conventional electromagnets adds to
the already high thermal load on the chamber, resulting in increased
chamber heating.

      The development of high temperature superconducting materials
of Yittrium-Barium-Copper oxides and related compounds which are
superconducting at liquid nitrogen temperatures solves this
experimental problem.  Coils constructed of high temperature
superconducting materials operated at liquid nitrogen temperature
provide a high magnetic field with very little resistance losses and
heating.  Superconducting coils can be made larger than the
conventional coils to provide more uniform magnetic fields in the
plasma chamber.  In addition due to the high fields available, higher
frequency multiples of the ECR resonance condition can be used.  This
results in  multiple resonance zones within the plasma and greater
uniformity of the plasma.

      The higher magnetic fields result in...