Method for releasing sample and plasma processing apparatus using same

Patent metadata

Field	Value
Publication number	US-11664233-B2
Application number	US-202117386892-A
Country	US
Kind code	B2
Filing date	Jul 28, 2021
Priority date	Jan 4, 2016
Publication date	May 30, 2023
Grant date	May 30, 2023

Abstract

A sample releasing method for releasing a sample subjected to plasma processing from a sample stage on which the sample is electrostatically attracted by applying DC voltage to an electrostatic chuck electrode, and the method includes: moving the sample subjected to the plasma processing upward above the sample stage; and after moving the sample, controlling the DC voltage such that an electric potential of the sample is to be smaller.

First claim

The invention claimed is:

1. A sample releasing method for releasing a sample subjected to plasma processing from a sample stage on which the sample is electrostatically attracted by applying DC voltage to an electrostatic chuck electrode, the method comprising the steps of:
turning off plasma for releasing the electrostatically attracted sample from the sample stage; and
after turning off the plasma, changing the DC voltage toward a positive direction compared to the DC voltage before turning off the plasma.

2. The sample releasing method according to claim 1 , further comprising the step of determining a change amount of the DC voltage toward the positive direction based on a floating potential of the plasma and an electrostatic capacity between the sample moved upward above the sample stage and a surface of the sample stage.

3. The sample releasing method according to claim 2 , further comprising the step of setting a change amount of the electric potential of the sample within a range between +10 to +20 volts.

4. The sample releasing method according to claim 1 , further comprising the step of, after turning off the plasma, setting the DC voltage to 0 volt.

5. The sample releasing method according to claim 1 , further comprising the step of setting time from turning off the plasma until the DC voltage is changed toward the positive direction within a range between 0.1 and 1.0 second.

6. The sample releasing method according to claim 1 , further comprising the step of determining a change amount of the DC voltage toward the positive direction based on a correlation between an electric potential of the sample released from the sample stage and the DC voltage.

7. The sample releasing method according to claim 1 , further comprising the steps of:
obtaining an electrostatic capacity ratio of an electrostatic capacity between the sample moved upward above the sample stage and a surface of the sample stage to an electrostatic capacity of the sample against the ground via a releasing mechanism which moves the sample upward from the sample stage; and
obtaining a change amount of the DC voltage toward the positive direction such that the electrostatic capacity ratio is substantially equal to a ratio of a change amount of the DC voltage toward the positive direction to a change amount of an electric potential of the sample.

8. The sample releasing method according to claim 1 , further comprising the step of conveying the sample subjected to the plasma processing from a processing chamber in which the sample is subjected to the plasma processing.

Assignees

• Hitachi High Tech Corp

Inventors

• Ishiguro Masaki
• Sumiya Masahiro
• Shirayone Shigeru
• Tamura Tomoyuki
• Ikenaga Kazuyuki

Classifications

• H10P72/722

  Details of electrostatic chucks · CPC title

• H10P72/0421

  for drying etching · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title

• H01J37/32706 Primary

  Polarising the substrate · CPC title

• H01J37/32715

  Workpiece holder · CPC title