Method for controlling potential of susceptor of plasma processing apparatus

Patent metadata

Field	Value
Publication number	US-2016240353-A1
Application number	US-201615008855-A
Country	US
Kind code	A1
Filing date	Jan 28, 2016
Priority date	Feb 16, 2015
Publication date	Aug 18, 2016
Grant date	—

Abstract

Disclosed is a method of suppressing abnormal discharge through a space between a space and a susceptor. A pulse-modulated high frequency wave is supplied from at least one of a first high frequency power supply and a second high frequency power supply. In addition, a DC voltage, which is pulse-modulated in synchronization with the modulated high frequency wave, is applied to the susceptor from a voltage application unit. A voltage value of the modulated DC voltage is set to reduce a difference between a potential of the substrate placed on an electrostatic chuck and a potential of the susceptor.

First claim

What is claimed is:

1 . A method for controlling a potential of a susceptor of a plasma processing apparatus that includes: a processing container; a susceptor formed of a conductor and provided within the processing container; an electrostatic chuck provided on the susceptor; a first high frequency power supply configured to generate a first high frequency wave for ion drawing-in; a second high frequency power supply configured to generate a second high frequency wave for plasma generation; a DC power supply configured to apply a positive polarity DC voltage to an electrode of the electrostatic chuck; and a voltage application unit configured to apply a voltage to the susceptor, the method comprising:
supplying a pulse modulated high frequency wave from at least one of the first high frequency power supply and the second high frequency power supply to the susceptor; and applying a DC voltage, which is pulse-modulated in synchronization with the modulated high frequency wave, from the voltage application unit to the susceptor, the modulated DC voltage having a voltage value set to reduce a difference between the potential of the substrate placed on the electrostatic chuck and the potential of the susceptor.

2 . The method of claim 1 , wherein the voltage application unit receives a pulse signal, which is synchronized with the modulated high frequency wave, from at least one of the first high frequency power supply and the second high frequency power supply, and applies a DC voltage, which is modulated in synchronization with the pulse signal, to the susceptor, the pulse signal having a first signal level in a first period when the modulated high frequency wave has a first power, and a second signal level in a second period when the modulated high frequency wave has a second power smaller than the first power.

3 . The method of claim 2 , wherein, in the supplying the modulated high frequency wave to the susceptor, the first high frequency wave is pulse-modulated, and the modulated high frequency wave is supplied to the susceptor, and
in the applying the modulated DC voltage to the susceptor, the voltage application unit applies the DC voltage to the susceptor in the first period, without applying the DC voltage to the susceptor in the second period.

4 . The method of claim 3 , wherein the voltage application unit applies a DC voltage having a voltage value, of which an absolute value becomes larger as a voltage amplitude on a transmission line, through which the modulated high frequency wave is supplied to the susceptor, increases, to the susceptor in the first period.

5 . The method of claim 3 , wherein the voltage application unit applies a DC voltage having a voltage value in a data table, which is associated with the power of the first high frequency wave, the power of the second high frequency wave, and the modulated frequency of the modulated frequency wave, to the susceptor in the first period.

6 . The method of claim 3 , wherein the voltage application unit applies a DC voltage according to a measurement value of a self-bias potential of the substrate to the susceptor in the first period.

7 . The method of claim 2 , wherein, in the supplying the modulated high frequency wave to the susceptor, the second high frequency wave is pulse-modulated, and the modulated high frequency wave is supplied to the susceptor, and
in the applying of the modulated DC voltage to the susceptor, the voltage application unit applies a first DC voltage having a first voltage value to the susceptor in the first period and a second DC voltage having a second voltage value, of which an absolute value is larger than an absolute value of the first voltage value, to the susceptor in the second period.

8 . The method of claim 7 , wherein the voltage application unit applies a DC voltage having a voltage value, of which an absolute value becomes larger as a voltage amplitude on a transmission line, through which the modulated high frequency wave is supplied to the susceptor, to the susceptor in each of the first and second periods.

9 . The method of claim 7 , wherein the voltage application unit applies a DC voltage having a voltage value in a data table, which is associated with the power of the first high frequency wave, the power of the second high frequency wave, and the modulated frequency of the modulated frequency wave, to the susceptor in each of the first and second periods.

10 . The method of claim 7 , wherein the voltage application unit applies a DC voltage according to a measurement value of a self-bias potential of the substrate in each of the first and second periods.

Assignees

• Tokyo Electron Ltd

Inventors

• Nagami Koichi

Classifications

• H01J2237/334

  Etching · CPC title

• H01J37/32715 Primary

  Workpiece holder · CPC title

• H01J37/32091 Primary

  the radio frequency energy being capacitively coupled to the plasma · CPC title

• H01J37/32577

  Electrical connecting means · CPC title

• H01J37/32568

  Relative arrangement or disposition of electrodes; moving means · CPC title