| 摘要 |
PURPOSE:To enable a simple and accurate detection of an etching endpoint by a method wherein a diffracted grid pattern is provided on the surface of a film to be etched when a dryetchng polycrystalline Si or the like is performed and a diffracted light is monitored with a photodetector by irradiating a laser beam. CONSTITUTION:A wafer 11 is placed in an etching chamber 10. The wafer 11 is formed on a silicon oxide film 21 provided, for example, on the surface of a single crystal Si substrate 20, and on this wafer 11 a diffracted grid pattern 23 consisting of a resist is formed. And when performing an etching, its diffracted light is detected by a photodetector 17 by irradiating a laser beam to a diffracted grid. At this time, the diffracted light intensity is saturated when a polycrystalline Si film etching is finished and the output of the photodetector is also saturated. Hereby, the detection of the endpoint of the etching can be performed accurately and easily. |
