| 摘要 |
PURPOSE: To accurately measure the thickness of a sample layer in a short time even when the thickness is thick by arranging a reference layer having nearly the same optical thickness as the sample layer has in front of the sample layer and measuring the progress of the intensity of light which varies depending upon the wavelength with a spectrophotometer. CONSTITUTION: A transparent sample layer 11 is irradiated with a beam in a sufficiently large wavelength region emitted from a light source 14 through a lens 12 and beam splitter 13. The beam component reflected by both boundary surfaces 11g and 11h are converged to the slit 15s of a spectrophotmeter 15 by means of the lens 12 through the beam splitter 13. By using this spectrophotometer 15, the progress of intensity of light which varies depending upon the wavelength is measured. Since the progress of intensity becomes the maximum and minimum due to the interference between beam components reflected by the surfaces 11g and 11f when the thickness 11b of the layer 11 is about 1-50μm, the thickness 11b of the layer 11 can be measured accurately. When the thickness 11b is thicker than 100μm, a reference layer 16 having parallel surfaces and nearly the same thickness as the layer 11 has is inserted into the optical path. When the layer 16 is inserted, additional interference which makes the detection and measurement of the thickness 11b easier occurs.
|
