Magnetron

• US 5,993,598 A
• Filed: 07/22/1997
• Issued: 11/30/1999
• Est. Priority Date: 07/30/1996
• Status: Expired due to Fees

• Current Assignee: The Dow Chemical Company (Dow, Inc.)
• Original Assignee: The Dow Chemical Company (Dow, Inc.)
• Inventors: Hu, Ing-Feng
• Primary Examiner(s): DANG, THI D
• Application Number:
  US08/898,158
• Time in Patent Office: 861 Days
• Field of Search: 156/345, 118/723 E, 204/298.37
• US Class Current: 156/345.46
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/3266 Magnetic control means

Abstract

Methods and devices for producing plasmas of more uniform density and greater height than plasmas generated by previously known magnetron-type plasma-generating devices. The present invention utilizes electrodes containing multiple magnets positioned such that like magnetic poles of the magnets are all facing in substantially the same direction.

Claims

1. A plasma-generating device, comprising two electrodes, at least one of said electrodes defining an electrode surface and containing two or more magnets, each magnet having two opposite magnetic poles, said magnets positioned such that like magnetic poles of said magnets are all facing in substantially the same direction, each magnetic pole of each magnet producing a magnetic field with the opposite magnetic pole on the same magnet;

each magnetic field having a component parallel to said electrode surface.

2. A plasma-generating device according to claim 1, wherein each magnet creates a single closed loop ExB drift path parallel to the surface of the electrode.

3. A plasma-generating device according to claim 1, wherein each magnet creates two closed loop ExB drift paths parallel to the surface of the electrode.

4. A plasma-generating device, comprising two electrodes, at least one electrode being a planar electrode and containing two or more magnets, each magnet having two opposite magnetic poles, said magnets positioned such that like magnetic poles of said magnets are in a single geometric plane parallel to the geometric plane of the planar electrode and the polarity of said magnets is perpendicular to the geometric plane of the planar electrode, each magnetic pole of each magnet producing a magnetic field with the opposite magnetic pole on the same magnet, each magnetic field having a component parallel to the geometric plane of the electrode.

5. A plasma-generating device according to claim 4, wherein each magnet creates a single closed loop EXB drift path parallel to the geometric plane of the planar electrode.

6. A plasma-generating device according to claim 4, wherein each magnet creates two closed loop ExB drift paths parallel to the geometric plane of the planar electrode.

7. A plasma-generating device, comprising:

a) two electrodes, at least one of said electrodes defining an electrode surface and containing two or more magnets, each magnet having two opposite magnetic poles, said magnets positioned such that like magnetic poles of said magnets are all facing in substantially the same direction, each magnetic pole of each magnet producing a magnetic field with the opposite magnetic pole on the same magnet, each magnetic field having a component parallel to the electrode surface, the magnets having sufficient strength to generate at least 100 gauss; and

b) a means for injecting gaseous reactants through at least one electrode, said means directing substantially all of said reactants through the magnetic fields.

8. A plasma-generating device according to claim 7, wherein each magnet creates a single closed loop ExB drift path parallel to the surface of the electrode.

9. A plasma-generating device according to claim 7, wherein each magnet creates two closed loop ExB drift paths parallel to the surface of the electrode.