Plasma processing apparatus and plasma processing method

• US 7,504,040 B2
• Filed: 02/28/2007
• Issued: 03/17/2009
• Est. Priority Date: 03/06/2001
• Status: Active Grant

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Tokyo Electron Limited
• Inventors: Tsuchiya, Hiroshi, Iijima, Etsuo
• Primary Examiner(s): OLSEN, ALLAN W
• Application Number:
  US11/711,769
• Publication Number:
  US 20070148364A1
• Time in Patent Office: 748 Days
• Field of Search: None
• US Class Current: 216/67
• CPC Class Codes: H01J 37/32082 Radio frequency generated discharge H01J37/32357, H01J37/32366, H01J37/32394 and H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01L 21/31116 by dry-etching
• CPC Class Codes: H01L 21/32137 of silicon-containing layers

Abstract

An RF power (Bottom RF) from a radio-frequency power source 12 is turned off (t5) and the supply of a He gas 14 to a back face of a wafer W is stopped (t5) when an end point detector 17 (EPD) detects an end point (t5), and a high-voltage DC power source 13 (HV) is turned off (t6) under the condition in which an RF power (Top RF) from a radio-frequency power source 11 is controlled to fall within a range in which etching does not progress and plasma discharge can be maintained (t5). This process enables the inhibition of the adhesion of particles while an etching amount is accurately controlled.

Claims

1. A plasma processing method, comprising:

a step of fixing a wafer via an electrostatic chuck;

a step of applying a first radio-frequency power for generating a plasma having a first frequency and a second radio-frequency power for controlling ion energy having a second frequency lower than the first frequency to thereby plasma-process the wafer;

a step of maintaining plasma discharge within a range in which the plasma processing does not progress by turning off the second radio-frequency power and lowering the first radio-frequency power or turning off the first radio-frequency power and lowering the second radio-frequency power after the plasma processing is finished;

a step of stopping supply of a coolant gas supplied to a back face of the wafer via the electrostatic chuck;

a step of stopping application of a direct-current voltage to the electrostatic chuck; and

a step of stopping the plasma discharge after stopping the application of the direct-current voltage.

2. The method as set forth in claim 1,

wherein, in the step of maintaining the plasma discharge, when the plasma processing is finished, the application of the second radio-frequency power is stopped and the first radio-frequency power is controlled to maintain the plasma discharge within a range in which the plasma processing does not progress.

3. The method as set forth in claim 1,

wherein, in the step of maintaining the plasma discharge, when the plasma processing is finished, the application of the first radio-frequency power is stopped and the second radio-frequency power is controlled to maintain the plasma discharge within a range in which the plasma processing does not progress.

4. The method as set forth in claim 1,

wherein, in the step of maintaining the plasma discharge, when the plasma processing is finished, the first radio-frequency power and the second radio-frequency power are controlled to maintain the plasma discharge within a range in which the plasma processing does not progress, and

wherein, in the step of stopping the plasma discharge, the application of the second radio-frequency power is stopped after the application of the first radio-frequency power is stopped.

5. The method as set forth in claim 1,

wherein, in the step of maintaining the plasma discharge, when the plasma processing is finished, the second radio-frequency power is maintained as it is and the first radio-frequency power is controlled to maintain the plasma discharge within a range in which the plasma processing does not progress, and

wherein, in the step of stopping the plasma discharge, the application of the second radio-frequency power is stopped after the application of the first radio-frequency power is stopped.

6. The method as set forth in claim 1,

wherein, the first radio-frequency power is applied to a top electrode and the second radio-frequency power is applied to a bottom electrode.

7. The method as set forth in claim 1,

wherein the first radio-frequency power and the second radio-frequency power are applied to a bottom electrode.