Plasma processing apparatus and plasma processing method

Patent metadata

Field	Value
Publication number	US-11032899-B2
Application number	US-201916565651-A
Country	US
Kind code	B2
Filing date	Sep 10, 2019
Priority date	Oct 2, 2018
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

A plasma processing apparatus includes a cooling plate having a fixing surface to which an upper electrode is fixed, the cooling plate having, on the fixing surface, an electrostatic chuck configured to attract the upper electrode by an attraction force generated by an applied voltage; a power supply configured to apply the voltage to the electrostatic chuck; and a power supply controller configured to control the power supply such that an absolute value of the voltage applied to the electrostatic chuck is increased based on a degree of consumption of the upper electrode.

First claim

We claim:

1. A plasma processing method performed in a plasma processing apparatus,
wherein the plasma processing apparatus comprises:
a cooling plate;
an upper electrode;
an electrostatic chuck provided between the cooling plate and the upper electrode and configured to attract the upper electrode;
a power supply configured to apply a voltage to the electrostatic chuck; and
a power supply controller configured to control an absolute value of the voltage applied to the electrostatic chuck from the power supply, and
wherein the plasma processing method comprises:
controlling the power supply such that the absolute value is increased based on a degree of consumption of the upper electrode.

2. The plasma processing method of claim 1 ,
wherein the plasma processing apparatus further comprises a measurement device, and
wherein the plasma processing method further comprises:
measuring a total processing time of a plasma processing by the measurement device; and
determining the degree of consumption of the upper electrode based on the measured total processing time.

3. The plasma processing method of claim 1 ,
wherein the plasma processing apparatus further comprises:
a measurement device configured to measure a total processing time of a plasma processing; and
a storage configured to store the absolute value of the voltage applied to the electrostatic chuck, and
wherein the plasma processing method further comprises:
storing, in the storage, voltage information indicating the absolute value corresponding to the total processing time such that the absolute value is increased as the total processing time of the plasma processing is increased;
measuring the total processing time of the plasma processing by the measurement device;
reading out, from the storage, the voltage information corresponding to the total processing time; and
applying, to the electrostatic chuck, the voltage corresponding to the read-out voltage information.

4. The plasma processing method of claim 1 ,
wherein the plasma processing apparatus further comprises:
a measurement device configured to measure a total processing time of a plasma processing; and
a storage configured to store relationship between consumption information indicating the degree of consumption of the upper electrode and voltage information indicating the absolute value of the voltage applied to the electrostatic chuck, and
wherein the plasma processing method further comprises:
determining the absolute value referring to the relationship.

5. The plasma processing method of claim 1 ,
wherein the controlling of the power supply is performed at a timing when a plasma processing on a wafer is begun.

6. The plasma processing method of claim 1 ,
wherein, in the controlling of the power supply, the power supply is controlled such that an attraction force of the electrostatic chuck to the upper electrode is gradually increased as a total processing time of a plasma processing is increased.

7. The plasma processing method of claim 1 ,
wherein the plasma processing apparatus further comprises a measurement device configured to measure a temperature of the upper electrode, and
wherein the plasma processing method further comprises:
measuring the temperature of the upper electrode by the measurement device;
calculating a difference between the measured temperature of the upper electrode and a previously measured temperature of an unused upper electrode; and
controlling, at a timing when the difference exceeds a preset threshold value, the power supply such that the absolute value of the voltage applied to the electrostatic chuck is increased.

8. The plasma processing method of claim 7 ,
wherein, in the controlling of the power supply, at the timing when the difference exceeds the preset threshold value, the power supply is controlled such that the absolute value of the voltage applied to the electrostatic chuck is increased from zero to a value larger than zero.

9. The plasma processing method of claim 1 ,
wherein the electrostatic chuck includes a central electrostatic chuck and a peripheral electrostatic chuck,
the power supply is configured to independently apply the voltage to the central electrostatic chuck and the peripheral electrostatic chuck, and
in the controlling of the power supply, the power supply is controlled such that the absolute value of the voltage applied to the central electrostatic chuck is increased based on the degree of consumption of the upper electrode while maintaining constant the absolute value of the voltage applied to the peripheral electrostatic chuck.

Assignees

• Tokyo Electron Ltd

Inventors

• Uchida Yohei
• Sato Tetsuji
• Yahata Shojiro
• Takase Taira

Classifications

• H05H1/28 Primary

  Cooling arrangements · CPC title

• H10P72/722

  Details of electrostatic chucks · CPC title

• H01J37/32715

  Workpiece holder · CPC title

• H01J37/32532

  Electrodes · CPC title

• H01J37/32522 Primary

  Temperature · CPC title