PLASMA PROCESSING APPARATUS

• US 20110108194A1
• Filed: 01/27/2010
• Published: 05/12/2011
• Est. Priority Date: 11/10/2009
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Nishio, Ryoji, YOSHIOKA, Ken, Yoshigai, Motohiko, Kawaguchi, Tadayoshi
• Granted Patent: US 9,039,865 B2
• Time in Patent Office: Days
• US Class Current: 156/345.35
• CPC Class Codes: H01J 37/321 the radio frequency energy being inductively coupled to the plasma
• CPC Class Codes: H01J 37/3211 Antennas, e.g. particular shapes of coils
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means

Abstract

The invention provides a plasma processing apparatus in which ring-like conductors 8a and 8b are arranged closed to and along an induction antenna 1 composed of an inner circumference coil 1a and an outer circumference coil 1b. Ring-like conductors 8a and 8b are each characterized in that the radius from the center of the apparatus and the cross-sectional shape of the conductor body varies along the circumferential angle of the coils. Since the mutual inductances between the ring-like conductors 8a and 8b and the induction antenna 1 and between the ring-like conductors 8a and 8b and the plasma along the circumferential position are controlled, it becomes possible to compensate for the coil currents varied along the circumference of the coils of the induction antenna 1, and to improve the non-uniformity in the circumferential direction of the current in the generated plasma.

Claims

1. A plasma processing apparatus comprising:

a vacuum processing chamber for generating plasma in the interior thereof;

a means for introducing gas into the vacuum processing chamber;

a stage for placing a sample disposed in the vacuum processing chamber;

an insulating dielectric window constituting an upper area of the vacuum processing chamber and covering a plasma generating space above the stage;

a coil-like induction antenna disposed on an outer side of the dielectric window for generating plasma within the plasma generating space in the vacuum processing chamber;

a high frequency power supply and a matching box for supplying current to the induction antenna; and

a conductor disposed near the induction antenna and arranged along the induction antenna for controlling the mutual inductances along the circumferential position between the conductor and the antenna and between the conductor and the plasma.

2. The plasma processing apparatus according to claim 1, wherein

the conductor disposed along the induction antenna is a ring-like conductor substantially concentric with the induction antenna, and the mutual inductances between the ring-like conductor and the induction antenna and between the ring-like conductor and the plasma are gradually varied according to the circumferential position of the ring-like conductor.

3. The plasma processing apparatus according to claim 2, wherein

a Faraday shield is disposed between the dielectric window and the induction antenna, capable of having the voltage thereof controlled via the matching box.

4. The plasma processing apparatus according to claim 3, wherein

the ring-like conductor is electrically in contact with the Faraday shield, wherein the conductor is disposed on an outermost circumference of a plurality of the induction antennas, and the radius of the inner circumference of the ring is gradually varied along the circumference of the ring.

5. The plasma processing apparatus according to claim 3, wherein

the ring-like conductor is electrically in contact with the Faraday shield, wherein the conductor is disposed on an innermost circumference of a plurality of the induction antennas, and the radius of the outer circumference of the ring is gradually varied along the circumference of the ring.

6. The plasma processing apparatus according to claim 3, wherein

the dielectric window has a circular truncated cone shape;

and

the ring-like conductor is electrically in contact with the Faraday shield, wherein the conductor is disposed along a tapered portion of the circular truncated cone from the lower portion of the cone, and the width of the ring-like conductor is gradually varied along the circumference of the ring.

7. The plasma processing apparatus according to claim 1, wherein

the dielectric window has a flat plate shape.

8. The plasma processing apparatus according to claim 7, wherein

the ring-like conductor is disposed on an outermost circumference of a plurality of the induction antennas, the radius of the inner circumference of the ring is gradually varied along the circumference of the ring, and the ring-like conductor is electrically in contact with a conductor cover covering the chamber having the induction antenna disposed thereto.

9. The plasma processing apparatus according to claim wherein

the ring-like conductor is arranged on an innermost circumference of the plurality of the induction antennas, and the radius of the outer circumference of the ring is gradually varied along the circumference of the ring.