Plasma processing apparatus

• US 10,037,868 B2
• Filed: 02/20/2015
• Issued: 07/31/2018
• Est. Priority Date: 03/25/2014
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Toyota, Koji, Yamamoto, Koichi, Yasui, Naoki
• Primary Examiner(s): DHINGRA, RAKESH KUMAR
• Application Number:
  US14/626,958
• Publication Number:
  US 20150279624A1
• Time in Patent Office: 1,257 Days
• Field of Search: 15634524-34528, 118715-733
• CPC Class Codes: H01J 37/32146 Amplitude modulation, includes pulsing
• CPC Class Codes: H01J 37/32192 Microwave generated discharge H01J37/32357, H01J37/32366, H01J37/32394, H01J37/32403 take precedence
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge

Abstract

The plasma processing apparatus includes: a processing chamber disposed inside a vacuum vessel; a first high-frequency power supply outputting a first high-frequency power for supplying an electric field to generate a plasma for use in processing a sample to be processed inside the processing chamber; a sample stage disposed inside the processing chamber with the sample placed on an upper surface thereof; a second high-frequency power supply intermittently outputting a second high-frequency power for generating a bias potential to an electrode disposed inside the sample stage and capable of variably adjusting the output time; and a function to adjust operation of the plasma processing apparatus using a result of detection of a temporal change in waveform of current or voltage in a transient state of the second high-frequency power in synchronism with start of the intermittent output of the second high-frequency power.

Claims

1. A plasma processing apparatus comprising:

a processing chamber disposed inside a vacuum vessel;

a first high-frequency power supply outputting a first high-frequency power for supplying an electric field to generate a plasma for use in processing a sample to be processed inside the processing chamber;

a sample stage disposed inside the processing chamber, on an upper surface of which the sample is placed;

a second high-frequency power supply intermittently outputting a second high-frequency power for generating a bias potential to an electrode disposed inside the sample stage so that a waveform of the second high-frequency power is synchronized with a reference cyclical signal and capable of variably adjusting the output time, and

a controller configured to adjust operation of the plasma processing apparatus using a result of detection of a temporal change in a waveform of current or voltage in a transient state of the second high-frequency power, the temporal change in the waveform in the transient state of the second high-frequency power being synchronized with a start of the intermittent output of the second high-frequency power and being detected by comparing, with each other, a plurality of waveforms of current or voltage which are detected in a predetermined time length in the transient state of the second high-frequency power.

2. The plasma processing apparatus according to claim 1, wherein

the temporal change in waveform of current or voltage in the transient state of the second high-frequency power is detected while synchronized with the reference cyclical signal.

3. The plasma processing apparatus according to claim 1, wherein

the temporal change in the waveform is detected by comparing the plurality of waveforms of current or voltage with each other, among the plurality of waveforms in a predetermined time length in the transient state of the second high-frequency power, the phases of the plurality of waveforms being aligned with each other.

4. The plasma processing apparatus according to claim 1, wherein

stop of the plasma processing apparatus or change of the processing condition is conducted using a result of detection of the temporal change in waveform of current or voltage in the transient state of the second high-frequency power.

5. The plasma processing apparatus according to claim 1, wherein

the waveform of the second high-frequency power is detected at every predetermined time interval in the transient state.

6. The plasma processing apparatus according to claim 1,

wherein the controller is further configured to detect the temporal change in the waveform by determining a time from generation of a self-bias voltage to a transition to a steady state of said waveform in which positive and negative components are substantially symmetrical.

7. A plasma processing apparatus comprising:

a processing chamber disposed inside a vacuum vessel;

a first high-frequency power supply outputting a first high-frequency power for supplying an electric field to generate plasma for use in processing a sample to be processed inside the processing chamber;

a sample stage disposed inside the processing chamber, on an upper surface of which the sample is placed;

a second high-frequency power supply outputting a second high-frequency power for generating a bias potential to an electrode disposed inside the sample stage so that a waveform of the second high-frequency power is synchronized with a reference cyclical signal and capable of variably adjusting ON time and OFF time of the output or a ratio thereof, and

a controller configured to adjust operation of the plasma processing apparatus using a result of detection of a temporal change in waveform of current or voltage in a transient state of the second high-frequency power, the temporal change in the waveform in the transient stage of the second high-frequency power being synchronized with a start of an ON period of the second high-frequency power and being detected by comparing, with each other, a plurality of waveforms of current or voltage which are detected in a predetermined time length in the transient state of the second high-frequency power.

8. The plasma processing apparatus according to claim 7, wherein

the temporal change in waveform of current or voltage in the transient state of the second high-frequency power is detected while synchronized with the reference cyclical signal.

9. The plasma processing apparatus according to claim 7,

wherein the temporal change in the waveform is detected by comparing the plurality of waveforms of current or voltage with each other, among the plurality of waveforms in a predetermined time length in the transient state of the second high-frequency power, the phases of the plurality of waveforms being aligned with each other.

10. The plasma processing apparatus according to claim 7,

wherein stopping of the plasma processing apparatus or changing of the processing condition is conducted using a result of detection of the temporal change in waveform of current or voltage in the transient state of the second high-frequency power.

11. The plasma processing apparatus according to claim 7,

wherein the controller is further configured to detect the temporal change in the waveform by determining a time from generation of a self-bias voltage to a transition to a steady state of said waveform in which positive and negative components are substantially symmetrical.