Plasma processing apparatus

• US 5,246,532 A
• Filed: 12/10/1992
• Issued: 09/21/1993
• Est. Priority Date: 10/26/1990
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Ishida, Tomoaki
• Primary Examiner(s): Hearn, Brian E.
• Assistant Examiner(s): GOUDREAU, GEORGE A
• Application Number:
  US07/990,797
• Time in Patent Office: 285 Days
• Field of Search: 156/345, 156/643, 118/723, 118/729, 118/728, 204/298.31, 204/298.02
• US Class Current: 156/345.46
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/3266 Magnetic control means
• CPC Class Codes: H01J 37/32697 Electrostatic control
• CPC Class Codes: Y10S 156/915 Differential etching apparatus including focus ring surrounding a wafer for plasma apparatus

Abstract

In a plasma processing method and a plasma processing apparatus, a substrate is processed in a plasma with a surrounding focus ring levitated by the repulsion between a magnet mounted in the focus ring and an electromagnet. The height of the focus ring relative to the substrate support is adjusted to an optimal height by adjusting the current flowing to the electromagnet. Therefore, it is possible to achieve an optimal height of the focus ring for the etching of each layer in a laminated film to enhance the uniformity of laminated film etching and to achieve precise etching.

Claims

1. A plasma processing apparatus comprising:

a processing container having a reactive gas inlet and a reactive gas outlet;

a high-frequency electrode disposed in said processing container for supporting a substrate;

a high-frequency power supply connected to said high-frequency electrode;

magnetic field generating means for generating a magnetic field in said processing container; and

a focus ring for surrounding the substrate and having a magnet therein for levitation above the high-frequency electrode by a magnetic field generated by said magnetic field generating means.

2. A plasma processing apparatus according to claim 1 wherein said magnetic field generating means is an electromagnet.

3. A plasma processing apparatus according to claim 2 wherein said electromagnet is embedded in said high-frequency electrode.

4. A plasma processing apparatus according to claim 2 wherein said container includes side walls and said electromagnet is disposed at a side wall of said processing container.

5. A plasma processing apparatus according to claim 2 wherein said electromagnet is disposed outside said processing container.

6. A plasma processing apparatus according to claim 1 wherein said magnet in said focus ring is an electromagnet.

7. A plasma processing apparatus according to claim 1 wherein said magnet in said focus ring is a permanent magnet.