PLASMA PROCESSING APPARATUS AND OPERATIONAL METHOD THEREOF

• US 20150021294A1
• Filed: 07/16/2014
• Published: 01/22/2015
• Est. Priority Date: 07/18/2013
• Status: Active Grant

• Current Assignee: Hitachi High-Tech Company Limited (Hitachi, Ltd.)
• Original Assignee: Hitachi High-Technologies Corporation (Hitachi, Ltd.)
• Inventors: Togami, Masahito, Usui, Tatehito, Hirota, Kosa, Inoue, Satomi, Nakamoto, Shigeru
• Granted Patent: US 9,767,997 B2
• Time in Patent Office: Days
• US Class Current: 216/60
• CPC Class Codes: H01J 2237/0266 electromagnetic
• CPC Class Codes: H01J 2237/2445 Photon detectors for X-rays, light, e.g. photomultipliers
• CPC Class Codes: H01J 2237/3341 Reactive etching
• CPC Class Codes: H01J 37/32458 Vessel
• CPC Class Codes: H01J 37/32908 Utilities
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01J 37/32972 Spectral analysis
• CPC Class Codes: H01J 37/3299 Feedback systems

Abstract

A plasma processing apparatus includes: a detector configured to detect a change in an intensity of light emission from plasma formed inside a processing chamber; and a unit configured to adjust conditions for forming the plasma or processing a wafer arranged inside the processing chamber using an output from the detector, wherein the detector detects a signal of the intensity of light emission at plural time instants before an arbitrary time instant during processing, and wherein the adjusting unit removes the component of a temporal change of a long cycle of the intensity of light emission from this detected signal and detects the component of a short temporal change of the intensity of light emission, and adjusts the conditions for forming the plasma or processing a wafer arranged inside the processing chamber based on the short temporal change of the detected intensity of light emission.

Claims

1. A plasma processing apparatus, comprising:

a processing chamber which is disposed inside a vacuum vessel;

a detector which is configured to detect a change in an intensity of light emission from plasma formed inside the processing chamber; and

an adjusting unit which is configured to adjust conditions for forming the plasma or processing a wafer arranged inside the processing chamber using an output from the detector, wherein

the detector detects a signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing, and wherein

the adjusting unit removes a component of a temporal change of a long cycle of the intensity of light emission from this detected signal and detects a component of a short temporal change of the intensity of light emission, and further adjusts the conditions for forming the plasma or processing a wafer arranged inside the processing chamber based on the short temporal change of the detected intensity of light emission.

2. The plasma processing apparatus according to claim 1, wherein the adjusting unit detects the component of a temporal change of a long cycle of the intensity of light emission from the signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing, using an infinite impulse response filter.

3. The plasma processing apparatus according to claim 1, wherein the adjusting unit reduces noise using an infinite impulse response filter from a signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing, and then removes the component of a temporal change of a long cycle of the intensity of light emission from the detected signal and detects the component of a short temporal change of the intensity of light emission.

4. The plasma processing apparatus according to claim 2, wherein the infinite impulse response filter is a Kalman filter.

5. The plasma processing apparatus according to claim 1, wherein the adjusting unit reduces noise using a Kalman filter using a higher extrapolation order, from the signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing, and then detects the component of a temporal change of a long cycle of the intensity of light emission from the signal whose noise is reduced, using a Kalman filter using a small extrapolation order, and removes the component of a temporal change of a long cycle of the intensity of light emission from the signal whose noise is reduced and detects the component of a short temporal change of the intensity of light emission.

6. A method for operating a plasma processing apparatus comprising:

a processing chamber arranged inside a vacuum vessel;

a detector configured to detect a change in an intensity of light emission from plasma formed inside the processing chamber; and

a unit configured to adjust conditions for forming the plasma or processing a wafer arranged inside the processing chamber using an output from the detector, the method comprising the steps of;

detecting, by the detector, a signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing;

removing the component of a temporal change of a long cycle of the intensity of light emission from the detected signal and detecting a component of a short temporal change of the intensity of light emission; and

adjusting the conditions for forming the plasma or processing a wafer arranged inside the processing chamber based on the short temporal change of the detected intensity of light emission.

7. The method for operating a plasma processing apparatus according to claim 6, further comprising the step of detecting the component of a temporal change of a long cycle of the intensity of light emission from the signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing, using an infinite impulse response filter.

8. The method for operating a plasma processing apparatus according to claim 6, further comprising the steps of:

reducing noise using an infinite impulse response filter from the signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing; and

after the step above, removing the component of a temporal change of a long cycle of the intensity of light emission from the detected signal and detecting the component of a short temporal change of the intensity of light emission.

9. The method for operating a plasma processing apparatus according to claim 7, wherein the infinite impulse response filter is a Kalman filter.

10. The method for operating a plasma processing apparatus according to claim 6, further comprising the steps of:

reducing noise from the signal of the intensity of light emission at a plurality of time instants before an arbitrary time instant during processing, using a Kalman filter; and

after the step above, detecting the component of a temporal change of a long cycle of the intensity of light emission from the signal whose noise is reduced, using a Kalman filter; and

removing the component of a temporal change of a long cycle of the intensity of light emission from the signal whose noise is reduced and detecting the component of a short temporal change of the intensity of light emission.