Method for detecting etching endpoint and etching apparatus and etching system using the method thereof

• US 5,626,714 A
• Filed: 12/06/1995
• Issued: 05/06/1997
• Est. Priority Date: 12/08/1994
• Status: Expired due to Term

• Current Assignee: Tokyo Electron Limited
• Original Assignee: Sumitomo Metal Industries Limited (Nippon Steel Corporation)
• Inventors: Nakamura, Toshiyuki, Tanaka, Hiroyuki, Hayami, Toshihiro, Miyazaki, Toshiya, Nakatsuka, Tadao
• Primary Examiner(s): Breneman, R. Bruce
• Assistant Examiner(s): ADJODHA, MICHAEL
• Application Number:
  US08/568,371
• Time in Patent Office: 517 Days
• Field of Search: 156/626.1, 216/59, 216/60, 204/298.32
• US Class Current: 216/60
• CPC Class Codes: B24B 37/013 Devices or means for detecting lapping completion
• CPC Class Codes: H01J 37/32935 Monitoring and controlling tubes by information coming from the object and/or discharge
• CPC Class Codes: H01J 37/32963 End-point detection
• CPC Class Codes: H01L 21/67069 for drying etching
• CPC Class Codes: H01L 21/67253 Process monitoring, e.g. flow or thickness monitoring
• CPC Class Codes: H01L 22/26 Acting in response to an ongoing measurement without interruption of processing, e.g. endpoint detection, in-situ thickness measurement endpoint detection arrangements in CMP apparatus B24B37/013, in discharge apparatus H01J37/32

Abstract

A method for detecting an etching endpoint and a plasma etching apparatus and a plasma etching system using such a device are disclosed, in which time series data of a signal corresponding to the amount of light of the plasma light generated during the plasma etching process are arithmetically processed, so that the change of light amount is corrected and an etching endpoint is detected from the time series data after the correction.

Claims

1. A method for detecting an etching endpoint, comprising steps of:

receiving plasma light generated during the plasma etching process;

producing time series data of a signal corresponding to the amount of received light;

performing an arithmetic operation on the time series data and thereby correcting the change of light amount, wherein said correction step corrects;

the time series data by a function holding the ratio between values apart from each other by a set period;

setting an unstable rise time in a test run, wherein said correction step corrects the time series data after for the unstable rise time;

calculating an average value of the time series data for said unstable rise time, wherein said correction step causes the initial value of the corrected time series data to coincide with said average value; and

detecting an etching endpoint from the corrected time series data.

2. A method for detecting an etching endpoint according to claim 1, wherein said correction step subtracts a predetermined value from the corrected time series data.