| 摘要 |
PURPOSE:To control the etching amount with high accuracy by detecting the intensity fluctuation of the fluorescence emitted from a semiconductor. CONSTITUTION:When a laser beam 6 is irradiated to a substrate 1 dipped in an etching liquid 3 from the outside of the vessel 4, the fluorescences 7 from the surface layer 1a and the inner layer 1b of the substrate are observed. The fluorescences 7 are detected 9 through a spectroscope 8 and the fluorescence intensities are observed 10. As the surface layer 1a is etched, the absorption in the layer 1a decreases and the intensity of the fluorescence from the layer 1b increases. At the moment when the layer 1a has been completely etched, the fluorescence emitted from the layer 1b suddenly decreases. Accordingly, by previously obtaining the relationship between the intensity of the fluorescence emitted from the substrate to be treated and the amount of etching being performed and observing the intensity of the fluorescence, etching of desired thickness can be performed with high accuracy. |
