Grooved insulator to reduce leakage current

Patent metadata

Field	Value
Publication number	US-9659753-B2
Application number	US-201414454493-A
Country	US
Kind code	B2
Filing date	Aug 7, 2014
Priority date	Aug 7, 2014
Publication date	May 23, 2017
Grant date	May 23, 2017

Abstract

A plasma source includes a first electrode and a second electrode having respective surfaces, and an insulator that is between and in contact with the electrodes. The electrode surfaces and the insulator surface substantially define a plasma cavity. The insulator surface defines one or more grooves configured to prevent deposition of material in a contiguous form on the insulator surface. A method of generating a plasma includes introducing one or more gases into a plasma cavity defined by a first electrode, a surface of an insulator that is in contact with the first electrode, and a second electrode that faces the first electrode. The insulator surface defines one or more grooves where portions of the insulator surface are not exposed to a central region of the cavity. The method further includes providing RF energy across the first and second electrodes to generate the plasma within the cavity.

First claim

We claim:

1. A plasma source, comprising:
a first electrode and a second electrode, the first and second electrodes comprising first and second electrode surfaces respectively; and
an insulator, comprising an insulator surface, disposed between and in contact with the first and second electrodes, wherein:
the first and second electrode surfaces and the insulator surface substantially define a plasma cavity;
the insulator forms a shoulder portion that is in contact with the second electrode surface, and a vertically recessed portion that is disposed axially inward with respect to the shoulder portion but is not in contact with the second electrode surface;
the insulator surface defines one or more grooves configured to prevent deposition of material in a contiguous form on the insulator surface exposed to the plasma cavity; and
the one or more grooves are vertical grooves formed within the vertically recessed portion.

2. The plasma source of claim 1 , wherein:
the second electrode surface is an upwardly facing, round and substantially planar surface where it contacts the insulator;
the insulator is substantially cylindrical, and is disposed atop and axially aligned with the second electrode surface, such that the insulator surface is an axially inwardly facing surface; and
the first electrode is disposed atop the insulator.

3. The plasma source of claim 1 , wherein the insulator comprises ceramic.

4. The plasma source of claim 1 , wherein at least one of the first and second electrodes comprises aluminum.

5. The plasma source of claim 4 , wherein the aluminum is plated with nickel or an alloy thereof.

6. The plasma source of claim 1 , wherein the one or more grooves is a single groove.

7. The plasma source of claim 1 , wherein the one or more grooves are a plurality of grooves.

8. The plasma source of claim 1 , wherein at least one of the one or more grooves comprises a rectilinear profile.

9. A method of manufacturing a plasma source, comprising:
forming ceramic material into a green body having a shape of an insulator, with one or more grooves formed in the green body;
sintering the green body to form the insulator;
disposing an insulator, with one or more grooves defined in an insulator surface thereof, in contact with a first electrode;
disposing a second electrode in contact with the insulator to form a cavity that is bounded by a surface of the first electrode, a surface of the second electrode, and the insulator surface;
providing an inlet gas line configured to introduce one or more gases into the cavity through at least one of the first electrode and the second electrode; and
providing an electrical coupling across the first and second electrodes, wherein:
the first and second electrodes are isolated from electrically contacting one another, by the insulator;
the cavity is configured such that when the one or more gases are introduced into the cavity and the electrical coupling provides RF energy across the first and second electrodes, a plasma forms within the cavity; and
the one or more grooves defined in the insulator surface are configured such that deposition of plasma sputtered material from the first or second electrode surfaces on the insulator surface is interrupted at the one or more grooves.

10. The method of manufacturing a plasma source of claim 9 , wherein forming the ceramic material into the green body having the shape of the insulator comprises casting the one or more grooves into the shape of the insulator.

11. The method of manufacturing a plasma source of claim 9 , wherein forming the ceramic material into the green body having the shape of the insulator comprises: casting ceramic material into the green body having the shape of the insulator, without the one or more grooves; and machining the one or more grooves into the green body.

12. A method of manufacturing a plasma source, comprising:
forming ceramic material into a green body having a shape of an insulator;
sintering the green body to form the insulator;
machining the insulator to form one or more grooves in an insulator surface thereof,
disposing the insulator in contact with a first electrode;
disposing a second electrode in contact with the insulator to form a cavity that is bounded by a surface of the first electrode, a surface of the second electrode, and the insulator surface;
providing an inlet gas line configured to introduce one or more gases into the cavity through at least one of the first electrode and the second electrode; and
providing an electrical coupling across the first and second electrodes, wherein:
the first and second electrodes are isolated from electrically contacting one another, by the insulator;
the cavity is configured such that when the one or more gases are introduced into the cavity and the electrical coupling provides RF energy across the first and second electrodes, a plasma forms within the cavity; and
the one or more grooves defined in the insulator surface are configured such that deposition of plasma sputtered material from the first or second electrode surfaces on the insulator surface is interrupted at the one or more grooves.

Assignees

• Applied Materials Inc

Inventors

• Cho Tae
• Kang Sang Won
• Yang Dongqing
• Lu Raymond W
• Hillman Peter
• Celeste Nicholas
• Tan Tien Fak
• Park Soonam
• Lubomirsky Dmitry

Classifications

• H01J37/3255 Primary

  Material · CPC title

• H01J37/32082

  Radio frequency generated discharge (H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence) · CPC title