Methods, apparatus, and systems involving ion beam generation

• US 6,777,699 B1
• Filed: 03/25/2003
• Issued: 08/17/2004
• Est. Priority Date: 03/25/2002
• Status: Expired due to Fees

• Current Assignee: NPL Associates, Inc.
• Original Assignee: George H. Miley, Yasser R. Shaban
• Inventors: Shaban, Yasser R., Miley, George H.
• Primary Examiner(s): Wells, Nikita
• Assistant Examiner(s): EL SHAMMAA, MARY A
• Application Number:
  US10/396,668
• Time in Patent Office: 511 Days
• Field of Search: 250/398, 250/423.R, 250/492.2, 250/492.21, 250/492.22, 250/492.23, 250/492.3, 219/121.36, 219/121.52, 315/111.81
• US Class Current: 250/492.3
• CPC Class Codes: G21K 1/093 by magnetic means
• CPC Class Codes: H01J 2237/08 Ion sources
• CPC Class Codes: H01J 27/16 using high-frequency excitation, e.g. microwave excitation

Abstract

A high-perveance steady state deuterium ion gun was developed using a magnetic-index resonator in an Inductive Coupling Radio Frequency (ICRF) configuration. This approach made it feasible to generate an ion beam within millimeter dimensions extracted by negative potential placed at several centimeters from the exit of the ion source. The ion gun allows high extraction efficiency and low beam divergence as compared to other approaches.

Claims

1. An apparatus, comprising:

a chamber coupled to a gas source;

a resonator operable to ionize gas received in the chamber from the gas source, the resonator including an RF electrical energy source, a helical coil wound about the chamber and coupled to the RF electrical energy source and an electrical shield positioned about the helical coil;

a magnetic indexing arrangement including several magnetic coils positioned about the chamber between the gas source and the resonator to control ion movement; and

a focusing arrangement including an aperture device, the aperture device including a portion that is electrically floating relative to a wall of the chamber coupled to the aperture device.

2. The apparatus of claim 1, wherein the focusing arrangement includes a magnetic focusing coil positioned between the resonator and the aperture device.

3. The apparatus of claim 1, further comprising a processing chamber coupled to the chamber to receive an ion beam from the aperture of the aperture device.

4. The apparatus of claim 3, further comprising an electrode positioned in the processing chamber and electrically isolated therefrom.

5. The apparatus of claim 4, further comprising a first conveyor subsystem coupled to the processing chamber to deliver work pieces to the processing chamber.

6. The apparatus of claim 5, further comprising a second conveyor subsystem coupled to the processing chamber to retrieve work pieces from the processing chamber.

7. The apparatus of claim 4, wherein the processing chamber is electrically grounded and the electrode is negatively biased relative to electrical ground.

8. The apparatus of claim 3, further comprising an inertial electrostatic containment device positioned in the processing chamber.

9. The apparatus of claim 1, wherein a first one of the magnetic coils is configured to generate a magnetic field strength greater than a second one of the magnetic coils.

10. The apparatus of claim 1, wherein the magnetic coils each include a winding that reverses direction.

11. A system, comprising:

an ion beam gun, the ion beam gun including;

a chamber coupled to a gas source;

means for ionizing gas received from the gas source, the ionizing means including a helical coil and an electrical shield positioned about the helical coil;

means for controlling movement of ions generated with the ionizing means; and

means for focusing ions received from the ionizing means, the focusing means including a magnetic coil and an aperture device, the aperture device including a portion that is electrically floating relative to a wall of the chamber coupled to the aperture device.

12. The system of claim 11, further comprising means for processing a work piece with an ion beam generated with the ion beam gun, the means for processing including means for conveying the work piece to and from a processing chamber, the processing chamber including an electrode positioned therein.

13. An apparatus, comprising:

an ion gun coupled to a gas source;

a resonator operable to ionize gas received in the chamber from the gas source, the resonator including an RF electrical energy source, a helical coil wound about a portion of the chamber and coupled to the RF electrical energy source and an electrical shield positioned about the helical coil;

a magnetic indexing arrangement including several magnetic coils positioned about the chamber between the gas source and the resonator, a first one and a second one of the magnetic coils having a magnetic field strength greater than a third one of the magnetic coils, the third one of the magnetic coils being positioned between the first one and the second one of the coils; and

a focusing arrangement including an aperture device, the aperture device including a portion that is electrically floating relative to a wall coupled to the aperture device.

14. The apparatus of claim 13, further comprising a processing chamber coupled to the chamber to receive an ion beam from the ion gun chamber.

15. The apparatus of claim 14, further comprising an electrode positioned in the processing chamber and electrically isolated therefrom.

16. The apparatus of claim 15, further comprising a first conveyor subsystem coupled to the processing chamber to deliver work pieces to the processing chamber.

17. The apparatus of claim 16, further comprising a second conveyor subsystem coupled to the processing chamber to retrieve work pieces from the processing chamber.

18. The apparatus of claim 15, wherein the processing chamber is electrically grounded and the electrode is negatively biased relative to electrical ground.

19. The apparatus of claim 14, further comprising an inertial electrostatic containment device positioned in the processing chamber.

20. A method, comprising:

providing a gas to an ion beam gun;

ionizing the gas with the ion beam gun, the ion beam gun including an RF resonator, the RF resonator including a helical coil coupled to an RF electrical energy source and an electrical shield positioned about the helical coil;

controlling ionized particles with several magnetic indexing coils;

focusing an ion beam generated with the ion beam gun, the ion beam gun including a focusing arrangement with an aperture device, the aperture device including a portion that is electrically floating relative to a wall coupled to the aperture device; and

providing the ion beam to a processing chamber.