| 摘要 |
PROBLEM TO BE SOLVED: To detect the relative dielectric constant of a porous material by a simple method or device. SOLUTION: A laser beam transmitted under the surface of a porous film 12 within a laser beam L irradiated on a semiconductor wafer 10 from a floodlight system is scattered by the interface of voids of the porous film 12 to emit diffusive light D. Diffusive light detection lenses 7a, 7b, 7c and 7d of a light receiving system converges the diffusive light, and photoelectric transducing elements 8a, 8b, 8c and 8d convert the intensity of the diffusive light into an electric signal. An analog processing circuit 51 carries out a pre-process such as noise elimination or digitization with respect to the electric signal inputted from the transducing elements 8a, 8b, 8c and 8d. A dielectric constant detection circuit 52 memorizes, as a computation formula, a correlation between the relative dielectric constant and the scattered light intensity according to the thickness of the porous film 12, and computes the relative dielectric constant of the porous film 12 from the output data from the processing circuit 51 and the thickness information of the porous film 12 by inputting the thickness information. COPYRIGHT: (C)2003,JPO
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