| 摘要 |
PROBLEM TO BE SOLVED: To highly precisely detect an end point of etching even if variation of a signal caused during etching is small. SOLUTION: A first signal caused in an etching device is acquired when a material to be etched is etched. A linear model or a non-linear model by a polynomial is obtained for the acquired first signal. An error between the first signal and a calculation value of the obtained model is obtained. When a time change rate of the error exceeds a prescribed threshold, the end point of etching is detected. Detection of the end point is transmitted to a control unit of an etching device. Deviation between a measured value and the model becomes large only at vicinity of the end point of etching. Consequently, the end point can be detected at a high SN ratio when a change of the first signal is small and gentle. COPYRIGHT: (C)2004,JPO
|
