| 摘要 |
PURPOSE: To enable measuring of a surface shape of a lower layer or an upper layer easily and quickly in a non-destructive manner by a method wherein a laser light is admitted into a sample at a plurality of incident angles to form a light cutting line on the sample and a film thickness is determined from an interfering light distribution within an incident surface of the reflected light from on the sample. CONSTITUTION: A light beam emitted from a laser 14 is turned to a linearly polarized light passing through a polarizer 16 to be expanded in diameter passing through a beam expander 18 and then, passed through a slit plate 20 to be shaped linearly in the section thereof. Then, the beam is condensed onto the sample 10 through a condenser lens 22. The slit formed on the slit plate 20 is along an incident surface with respect to the sample 10 in the longitudinal direction thereof. The incident surface passes a normal and Y axis on the sample 10. A luminous flux is admitted into the sample 10 at an angle of incidence within a range ofθi-Δθ-θi+Δθto form a light cutting line in the direction of the X axis at the right angle to the Y axis. A film thickness of an upper layer of the sample is determined based on an interfering light intensity distribution within the incident surface of the reflected light from the sample 10. Moreover, the surface shape of the lower layer is determined based on an image of the light cutting line and the film thickness is added to the results to determine the surface shape of the upper layer.
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