| 摘要 |
PURPOSE:To find the installation of a substrate to be defective by a method wherein one or more openings are provided in a second electrode opposing to a first electrode of the parallel plane type, whereon the Si substrate is placed, and a light emission source and a photodetector are provided on a line normal to the surface of the first electrode, which passes through the openings. CONSTITUTION:An Si substrate 1 is placed on an electrode 2. A part of the surface of the substrate 1, which is located right under the opening 4 of an electrode 3, is irradiated with the light of an LED5, which has an infrared wavelength with a larger reflection coefficient to that of the photoresist film. When the substrate 1 is not parallel to the surface of the electrode 2 due to foreign substances and so forth on the electrode 2, the reflected light does not pass through the opening 4 or the reflected light can not be detected by a photodetector 6 as being a feeble light. Moreover, when a laser element with a single wavelength is used as the light emission source 5, the state that the substrate 1 is floating from the electrode 2 can be also discriminated as the distance can be measured by means of the laser element. According to this device, the failure of installation of the substrate can be prevented by detecting the defective installation of the substrate before the plasma processing. |
