| 摘要 |
PROBLEM TO BE SOLVED: To directly measure the film thickness of an unknown sample without using any standard sample by measuring the intensity of diffracted rays of X rays radiated form a substrate through a thin film to be measured and finding the thickness of the thin film by utilizing the relation between the attenuation factor of the diffracted rays and the thickness of the thin film. SOLUTION: When the intensity of an incident beam, the cross-sectional area of a sample, and the angle between the sample and incident X-rays are respectively represented by Io (erg/cm<2> /sec), 1cm<2> , andα, the intensity dIx of X rays diffracted by a thin film having a thickness dx and a length I is found from formula I. Then the depth (t) at which 99% of the intensity of diffracted rays diffracted by a sample having an infinite thickness is obtained is found from formula IV as the intruding depth of the X rays. When the incident angle at which the X rays are diffracted at the boundary between a thin film 11 and a substrate 10 is used as the incident angle of the X rays in the formula IV, the intruding depth to the upper-layer section of the substrate 10 from the surface of the thin film 11 can be found and the thickness of the thin film 11 can be found. The curve of attenuation of the X rays by the thin film 11 is found by correcting the measured intensity of the diffracted rays of the X rays. The thickness of the thin film 11 is found by substituting the incident angle obtained from the curve of attenuation into the formula VI.
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