Plasma processing apparatus and operational method thereof

• US 9,767,997 B2
• Filed: 07/16/2014
• Issued: 09/19/2017
• 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
• Primary Examiner(s): DHINGRA, RAKESH KUMAR
• Application Number:
  US14/333,502
• Publication Number:
  US 20150021294A1
• Time in Patent Office: 1,161 Days
• Field of Search: 15634525, 15634524-34528
• 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 disposed inside a vacuum vessel, the processing chamber being configured to host hold a wafer for processing using a plasma therein;

a detector configured to detect an intensity of light emission from the plasma at a plurality of time intervals before a time instant during the processing;

a first filter configured to reduce noise components from a signal indicating the intensity of light emission from the plasma inside the processing chamber which is detected by the detector;

a second filter configured to reduce changing change components from the signal, the change components being associated with a change occurring for a period longer than a predetermined period, the change pertaining to state of a film to be processed or the state of particles in plasma or the state inside the processing chamber; and

a determination unit configured to use the signal to determine whether the processing is complete.

2. The plasma processing apparatus according to claim 1, wherein the second filter is an infinite impulse response filter.

3. The plasma processing apparatus according to claim 2, wherein the first filter is an infinite impulse response filter.

4. The plasma processing apparatus according to claim 1, wherein the second filter is a Kalman filter.

5. The plasma processing apparatus according to claim 4, wherein the first filter is a Kalman filter.

6. The plasma processing apparatus according to claim 1, wherein the first filter is a Kalman filter using a higher extrapolation order than an extrapolation order of the second filter and the second filter is a Kalman filter using a lower extrapolation order than the extrapolation order of the first filter.