SiC coating in an ion implanter

Patent metadata

Field	Value
Publication number	US-9793086-B2
Application number	US-201615175501-A
Country	US
Kind code	B2
Filing date	Jun 7, 2016
Priority date	Sep 27, 2013
Publication date	Oct 17, 2017
Grant date	Oct 17, 2017

Abstract

An ion implanter has a coating of low resistivity silicon carbide on one or more of the conductive surfaces that are exposed to ions. For example, ions are generated in an ion source chamber, and the interior surfaces of the walls are coated with low resistivity silicon carbide. Since silicon carbide is hard and resistant to sputtering, this may reduce the amount of contaminant ions that are introduced into the ion beam that is extracted from the ion source chamber. In some embodiments, the extraction electrodes are also coated with silicon carbide to reduce the contaminant ions introduced by these components.

First claim

What is claimed is:

1. An ion implanter, comprising:
an ion source comprising an ion source chamber having a first wall, an opposite conductive second wall and a plurality of conductive side walls, where an extraction aperture is disposed in said conductive second wall; and
a plurality of conductive liners, each disposed against and in electrical communication with a respective interior surface of said conductive side walls;
wherein the conductive second wall and side walls are in communication with a first bias voltage; and
wherein at least one of said conductive liners is coated with low resistivity silicon carbide.

2. The ion implanter of claim 1 , wherein said low resistivity silicon carbide has a resistivity of less than 1 ohm-cm.

3. The ion implanter of claim 1 , wherein an interior surface of said conductive second wall is coated with said low resistivity silicon carbide.

4. The ion implanter of claim 1 , further comprising an extraction electrode assembly disposed proximate said extraction aperture and outside said ion source chamber, said extraction electrode assembly comprising one or more conductive electrodes in communication with one or more second bias voltages to attract ions from the ion source chamber through the extraction aperture, and
wherein a surface of said one or more conductive electrodes is coated with said low resistivity silicon carbide.

5. The ion implanter of claim 4 , wherein each of said one or more conductive electrodes comprise a respective aperture, and a portion of at least one of said one or more conductive electrodes surrounding said respective aperture is coated with said low resistivity silicon carbide.

6. An ion implanter, comprising:
an ion source comprising an ion source chamber having a first wall, an opposite conductive second wall and a plurality of conductive side walls, where an extraction aperture is disposed in said conductive second wall; and
an extraction electrode assembly disposed proximate said extraction aperture and outside said ion source chamber, said extraction electrode assembly comprising one or more conductive electrodes;
wherein the conductive second wall and the plurality of conductive side walls are in communication with a first bias voltage and the one or more conductive electrodes are in communication with one or more second bias voltages, wherein a voltage difference between the first bias voltage and the second bias voltage serves to attract positive ions from the ion source chamber through the extraction aperture;
wherein at least one of an interior surface of said conductive second wall, an interior surface of one of the plurality of side walls and said extraction electrode assembly is coated with low resistivity silicon carbide; and
wherein said low resistivity silicon carbide has a resistivity of less than 1 ohm-cm.

7. The ion implanter of claim 6 , further comprising a plurality of conductive liners, each disposed against and in electrical communication with a respective interior surface of said conductive side walls.

8. The ion implanter of claim 7 , wherein said plurality of conductive liners each comprise a first surface facing an interior of said ion source chamber and an opposite second surface facing a respective sidewall, and said first surface is coated with low resistivity silicon carbide.

9. The ion implanter of claim 6 , wherein said interior surface of said conductive second wall is coated with said low resistivity silicon carbide.

10. The ion implanter of claim 6 , wherein a surface of said one or more conductive electrodes is coated with said low resistivity silicon carbide.

11. The ion implanter of claim 10 , wherein each of said one or more conductive electrodes comprise a respective aperture, and a portion of at least one of said one or more conductive electrodes surrounding said respective aperture is coated with said low resistivity silicon carbide.

12. An ion implanter, comprising:
an ion source comprising an ion source chamber having a first wall, an opposite conductive second wall and a plurality of conductive side walls, where an extraction aperture is disposed in said conductive second wall;
a plurality of conductive liners, each disposed against and in electrical communication with a respective interior surface of said conductive side walls, each of said liners comprising a first surface facing an interior of said ion source chamber and an opposite second surface facing a respective sidewall, wherein said first surface is coated with low resistivity silicon carbide; and
an extraction electrode assembly disposed proximate said extraction aperture and outside said ion source chamber, said extraction electrode assembly comprising one or more conductive electrodes, each having a respective aperture, wherein a portion of at least one electrode surrounding said respective aperture is coated with low resistivity silicon carbide;
wherein said low resistivity silicon carbide has a resistivity of less than 1 ohm-cm;
and wherein the conductive side walls are in communication with a first bias voltage and the one or more conductive electrodes are in communication with one or more second bias voltages to attract ions from the ion source chamber through the extraction aperture.

13. The ion implanter of claim 12 , wherein an interior surface of said conductive second wall is coated with said low resistivity silicon carbide.

14. The ion implanter of claim 13 , wherein a region where said conductive second wall and said conductive side walls attach is not coated with said low resistivity silicon carbide.

Assignees

• Varian Semiconductor Equipment Ass Inc

Inventors

• Mason Robert J
• Patel Shardul S
• Bettencourt Robert H
• Miller Timothy J

Classifications

• H01J2237/061

  Construction · CPC title

• H01J2237/022

  Avoiding or removing foreign or contaminating particles, debris or deposits on sample or tube · CPC title

• H01J2237/083

  Beam forming · CPC title

• H01J37/08 Primary

  Ion sources; Ion guns · CPC title

• H01J37/12

  electrostatic · CPC title