Single beam plasma source

Patent metadata

Field	Value
Publication number	US-2022013324-A1
Application number	US-202117482833-A
Country	US
Kind code	A1
Filing date	Sep 23, 2021
Priority date	Mar 26, 2019
Publication date	Jan 13, 2022
Grant date	—

Abstract

A single beam plasma or ion source apparatus, including multiple and different power sources, is provided. An aspect of the present apparatus and method employs simultaneous excitation of an ion source by DC and AC, or DC and RF power supplies. Another aspect employs an ion source including multiple magnets and magnetic shunts arranged in a generally E cross-sectional shape.

First claim

1 . An ion source apparatus comprising:
(a) an anode comprising at least one magnetic conductor and an open plasma area being located within a hollow central area of the anode; (b) a cathode comprising a cap having an outlet opening therethough; (c) a direct current power source connected to the anode; (d) an alternating current or radio frequency power source connected to the anode; and (e) ionization operably occurring within the plasma area inside the anode at least partially due to excitation by the direct and alternating current power sources.

2 . The apparatus of claim 1 , wherein the at least one magnetic conductor comprises multiple magnets or magnetic shunts which create a magnetic flux with a central dip in an open space wherein the plasma is created.

3 . The apparatus of claim 2 , wherein the magnets or magnetic shunts are arranged in a substantially E cross-sectional shape, and with a body or the cap of the cathode being a magnetic metal.

4 . The apparatus of claim 1 , wherein:
the cap of the cathode is magnetic and removable; the cap is isolated from a body of the anode which surrounds the at least one magnetic conductor of the anode; and an ion source discharge voltage is between 1-10 volts.

5 . The apparatus of claim 1 , further comprising:
a sputtering source acted upon by ions emitted through the outlet opening; and a vacuum chamber within which is located the anode and the cathode, the chamber having an operating pressure of 1 mTorr to 500 mTorr.

6 . The apparatus of claim 1 , further comprising ions emitted through the outlet opening performing cleaning or evaporation deposition of thin films.

7 . The apparatus of claim 1 , further comprising a single ion beam emitted through the outlet opening, the outlet opening being circular and having a cross-sectional diameter or width of 3-30 mm.

8 . The apparatus of claim 1 , further comprising:
a vacuum chamber within which is located the anode and cathode; a reactive gas located in the chamber; and a single ion beam, without a hollow center, created by the reactive gas and the excitation by the power sources.

9 . The apparatus of claim 1 , wherein there is simultaneous excitation of the ion source apparatus by:
both the direct current and the alternating current power sources; or both the direct current and the radio frequency power sources.

10 . The apparatus of claim 1 , wherein the cathode is set at a floating potential.

11 . The apparatus of claim 1 , wherein:
the cathode is set at ground potential; and the ionization enhances sputtering.

12 . The apparatus of claim 1 , further comprising:
a first insulator located adjacent to a middle segment of the body of the anode laterally defining part of the open plasma area opposite the outlet opening of the anode, a peripheral edge of the first insulator having a lateral dimension at or less than innermost edges of the magnetic conductor of the anode; the magnetic conductor being at least one of magnets or magnetic shunts; and at least a second insulator, having a hollow center and being longitudinally spaced away from the first insulator, and a lateral periphery of the second insulator having a greater dimension than the lateral dimension of the first insulator.

13 . An ion source apparatus comprising:
(a) an anode comprising at least one magnetic conductor and an open plasma area being located within a hollow central area of the anode; (b) a cathode comprising a cap having an outlet opening therethough; (c) a direct current power source connected to the anode, direct current power from the source being 10-300 volts; (d) an alternating current or radio frequency power source connected to the anode; (e) a vacuum chamber within which the anode and the cathode are located; (f) a sputter deposition source located within the vacuum chamber; and (g) a single ion beam emitted from the outlet opening of the cathode containing ions being substantially uniformly distributed around a center axis viewed in cross-section.

14 . The apparatus of claim 13 , wherein the radio frequency power source is connected to the anode.

15 . The apparatus of claim 13 , wherein the alternating current power source is connected to the anode.

16 . The apparatus of claim 13 , further comprising a filter network isolates the power sources.

17 . The apparatus of claim 13 , wherein there is simultaneous excitation of the ion source apparatus by:
both the direct current and the alternating current power sources; or both the direct current and the radio frequency power sources.

18 . The apparatus of claim 13 , further comprising:
a first insulator located adjacent to a middle segment of the body of the anode laterally defining part of the open plasma area opposite the outlet opening of the anode a peripheral edge of the first insulator having a lateral dimension at or less than innermost edges of the magnetic conductor of the anode; the magnetic conductor being at least one of magnets or magnetic shunts; and at least a second insulator, having a hollow center and being longitudinally spaced away from the first insulator, and a lateral periphery of the second insulator having a greater dimension than the lateral dimension of the first insulator.

19 . A method of using an ion source, the method comprising:
(a) supplying direct current electricity to an anode, which includes a magnet; (b) supplying at least one of: alternating electricity and a radio frequency, to the anode simultaneous with step (a); (c) setting a cathode, surrounding a portion of the anode, to a floating, ground or bias potential, the cathode including an outlet opening; (d) ionizing reactive gas within a vacuum, due at least in part to steps (a) and (b), to emit a single ion beam, without a hollow center, out of the outlet opening.

20 . The method of claim 19 , further comprising sputtering a deposition material with the ion beam within the vacuum.

21 . An ion source apparatus comprising:
(a) an anode comprising at least one magnetic conductor and an open plasma area being located within the anode; (b) a cathode comprising a cap having an outlet opening therethough; (c) a direct current power source connected to the anode; (d) an alternating current or radio frequency power source connected to the anode; (e) ionization operably occurring within the plasma area inside the anode at least partially due to excitation by the direct and alternating current power sources; (f) the cap of the cathode being magnetic and removable; (g) the cap being isolated from a body of the anode which surrounds the at least one magnetic conductor of the anode; and (h) an ion source discharge voltage being between 1-10 volts.

22 . The apparatus of claim 21 , wherein:
the at least one magnetic conductor comprises multiple magnets or magnetic shunts which create a magnetic flux in an open space wherein the plasma is created; and the magnets or magnetic shunts are arranged in a substantially E cross-sectional shape, and with a body or the cap of the cathode being a magnetic metal.

23 . The apparatus of claim 21 , further comprising:
a vacuum chamber within which is located the anode and cathode; a reactive gas located in the chamber; a single ion beam, without a hollow center, created by the reactive gas and the excitation by the power sources; and ions emitted through the outlet opening performing cleaning or evaporation deposition o

Assignees

• Univ Michigan State

Inventors

• Fan Qi Hua

Classifications

• H01J2237/3146

  Ion beam bombardment sputtering · CPC title

• C23C14/35

  by application of a magnetic field, e.g. magnetron sputtering {(C23C14/3457 takes precedence)} · CPC title

• H01J37/08 Primary

  Ion sources; Ion guns · CPC title

• H01J27/146 Primary

  End-Hall type ion sources, wherein the magnetic field confines the electrons in a central cylinder · CPC title

• H01J2237/0815

  Methods of ionisation · CPC title