Plasma processing apparatus and plasma processing method

Patent metadata

Field	Value
Publication number	US-2016336185-A1
Application number	US-201615057162-A
Country	US
Kind code	A1
Filing date	Mar 1, 2016
Priority date	May 12, 2015
Publication date	Nov 17, 2016
Grant date	—

Abstract

A plasma processing apparatus includes a plasma processing chamber processing a sample using plasma, a radio frequency power supply supplying radio frequency power for generating the plasma, a sample stage including an electrode electrostatically chucking the sample, mounting the sample thereon, a DC power supply applying DC voltage to the electrode, and a control device shifting the DC voltage previously set, in a negative direction by a first shift amount during discharge of the plasma, shifting the DC voltage having been shifted in the negative direction by the first shift amount, in a positive direction by a second shift amount after the discharge of the plasma. The first shift amount has a value changing potential over a surface of the sample to 0 V, upon shifting the DC voltage in the positive direction. The second shift amount has a value obtained based on a floating potential of the plasma.

First claim

What is claimed is:

1 . A plasma processing apparatus comprising:
a plasma processing chamber configured to process a sample using plasma; a radio frequency power supply configured to supply radio frequency power for generation of the plasma; a sample stage including an electrode configured to electrostatically chuck the sample, the sample stage configured to mount the sample thereon; a DC power supply configured to apply DC voltage to the electrode; and a control device configured to shift the DC voltage previously set, in a negative direction by a first shift amount during discharge of the plasma, and shift the DC voltage having been shifted in the negative direction by the first shift amount, in a positive direction by a second shift amount after the discharge of the plasma, wherein the first shift amount has a value changing potential over a surface of the sample to 0 V, upon shifting the DC voltage in the positive direction, and the second shift amount has a value obtained based on a floating potential of the plasma.

2 . The plasma processing apparatus according to claim 1 , wherein
the electrode includes a first electrode to which a first DC voltage is applied by the DC power supply, and a second electrode to which a second DC voltage having a polarity different from that of the first DC voltage is applied by the DC power supply.

3 . The plasma processing apparatus according to claim 2 , wherein
the first shift amount is equal to the second shift amount.

4 . The plasma processing apparatus according to claim 3 , wherein
the second shift amount is not less than 15 V.

5 . The plasma processing apparatus according to claim 2 , wherein
the control device controls a value of the first DC voltage and a value of the second DC voltage, before generation of the plasma such that the sample has a potential of 0, the potential being generated due to a difference between an impedance between the first electrode and the sample, and an impedance between the second electrode and the sample.

6 . The plasma processing apparatus according to claim 1 , further comprising:
a detection unit configured to detect discharge of the plasma and end of the discharge, the detection unit including: a sensor configured to monitor an output voltage of the radio frequency power supply, a sensor configured to monitor optical emission of the plasma, or a sensor configured to monitor an ion current from the plasma.

7 . A plasma processing method using a plasma processing apparatus including a plasma processing chamber configured to process a sample using plasma, a radio frequency power supply configured to supply radio frequency power for generation of the plasma, a sample stage including an electrode configured to electrostatically chuck the sample, the sample stage configured to mount the sample thereon, and a DC power supply configured to apply DC voltage to the electrode, the plasma processing method comprising:
shifting the DC voltage previously set, in a negative direction by a first shift amount during discharge of the plasma; and shifting the DC voltage having been shifted in the negative direction by the first shift amount, in a positive direction by a second shift amount after the discharge of the plasma, wherein the first shift amount has a value changing potential over a surface of the sample to 0 V, upon shifting the DC voltage in the positive direction, and the second shift amount has a value obtained based on a floating potential of the plasma.

8 . The plasma processing method according to claim 7 , wherein
the electrode includes: a first electrode to which a first DC voltage is applied by the DC power supply, and a second electrode to which a second DC voltage having a polarity different from that of the first DC voltage is applied by the DC power supply, and the first shift, amount is equal to the second shift amount.

9 . The plasma processing method according to claim 7 , wherein
the electrode includes: a first electrode to which a first DC voltage is applied by the DC power supply; and a second electrode to which a second DC voltage having a polarity different from that of the first DC voltage is applied by the DC power supply, and a value of the first DC voltage and a value of the second DC voltage are controlled before generation of the plasma, such that the sample has a potential of 0, the potential being generated due to a difference between an impedance between the first electrode and the sample, and an impedance between the second electrode and the sample.

Assignees

• Hitachi High Tech Corp

Inventors

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

Classifications

• H10P72/72

  using electrostatic chucks · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title

• H01J37/32577

  Electrical connecting means · CPC title

• H01J37/32706

  Polarising the substrate · CPC title

• H01J37/32972

  Spectral analysis · CPC title