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US 5,626,714 AGranted
Method for detecting etching endpoint and etching apparatus and etching system using the method thereof
AssigneeSumitomo Metal Industries, Ltd.
InventorsToshiya Miyazaki, Toshihiro Hayami, Tadao Nakatsuka, Hiroyuki Tanaka, Toshiyuki Nakamura
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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.
Claims2
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.
5 more elements
Dependencies are inferred from the claim text.