Methods and apparatus for tuning a set of plasma processing steps

• US 7,138,067 B2
• Filed: 09/27/2004
• Issued: 11/21/2006
• Est. Priority Date: 09/27/2004
• Status: Active Grant

• Current Assignee: Lam Research Corporation
• Original Assignee: Lam Research Corporation
• Inventors: Vahedi, Vahid, Singh, Harmeet, Daugherty, John, Chen, Anthony
• Primary Examiner(s): Ahmed, Shamim
• Application Number:
  US10/951,552
• Publication Number:
  US 20060065628A1
• Time in Patent Office: 785 Days
• Field of Search: 216/58, 216/59, 216/67, 438/706, 438/710, 156/345.23
• US Class Current: 216/67
• CPC Class Codes: C03C 15/00 Surface treatment of glass, not in the form of fibres or filaments, by etching etching or surface-brightening compositions, in general C09K13/00
• CPC Class Codes: C03C 23/006 by plasma or corona discharge
• CPC Class Codes: H01J 37/32623 Mechanical discharge control means
• CPC Class Codes: H01J 37/32642 Focus rings
• CPC Class Codes: H01L 21/32136 using plasmas

Abstract

In a plasma processing system, a method of tuning of a set of plasma processing steps is disclosed. The method includes striking a first plasma comprising neutrals and ions in a plasma reactor of the plasma processing system. The method also includes etching in a first etching step a set of layers on a substrate; positioning a movable uniformity ring around the substrate, wherein a bottom surface of the uniformity ring is about the same height as a top surface of the substrate; and striking a second plasma consisting essentially of neutrals in the plasma reactor of the plasma processing system. The method further includes etching in a second etching step the set of layers on the substrate; and wherein the etching in the first step and the etching in the second step are substantially uniform.

Claims

1. In a plasma processing system, a method of tuning of a set of plasma processing steps, comprising:

striking a first plasma comprising neutrals and ions in a plasma reactor of said plasma processing system;

etching in a first etching step a set of layers on a substrate;

positioning a movable uniformity ring around said substrate, wherein a bottom surface of said uniformity ring is about the same height as a top surface of said substrate;

striking a second plasma consisting essentially of neutrals in said plasma reactor of said plasma processing system;

etching in a second etching step said set of layers on said substrate;

wherein said etching in said first step and said etching in said second step are substantially uniform.

2. The method of claim 1, wherein a step of cleaning said plasma reactor is conducted prior to the step of striking said first plasma.

3. The method of claim 2, wherein said step of cleaning said plasma reactor comprises a waterless auto clean process.

4. The method of claim 1, wherein said movable uniformity ring comprises a material resistant to plasma attack.

5. The method of claim 4, wherein said material includes one of quartz, Y₂O₃, yttrium, CeO₂, cerium, AlO₃, aluminum, ZrO₂, and zirconium.

6. The method of claim 1, wherein said movable uniformity ring comprises a material that generates a set volatile etch products when exposed to said first plasma and said second plasma.

7. The method of claim 4, wherein said material includes one of Teflon, Vespel, plastic, and ceramic.

8. The method of claim 1, where said movable uniformity ring is heated.

9. In a plasma processing system, including a plasma reactor, a method of tuning of a set of plasma processing steps, comprising:

positioning said movable uniformity ring around said substrate, wherein a top surface of said uniformity ring is at a first height above a bottom surface of said plasma reactor;

striking a first plasma comprising neutrals and ions in said plasma reactor;

etching in a first etching step a set of layers on a substrate, wherein a first amount of etch uniformity on said substrate is achieved;

repositioning said movable uniformity ring around said substrate, wherein said top surface of said uniformity ring is at a second height above said bottom surface of said plasma reactor;

striking a second plasma consisting essentially of neutrals;

etching in a second etching step said set of layers on said substrate, wherein a second amount of etch uniformity on said substrate is achieved;

wherein said first amount of etch uniformity and said second amount of etch uniformity are substantially uniform.