| 摘要 |
PURPOSE:To eliminate the need for a special light-shielded chamber while simplifying the mechanism of an inspector, by making reflected light or scattered light focused with an optical fiber bundle into a photoelectric converter to convert only light with a single wavelength into an electrical signal from among beams of incident light. CONSTITUTION:A parallel beam 12 with a single wavelength lambda incident from a laser oscillator 11 is deflected with a deflector 13 within one plane repeatedly at a specified cycle, made incident into an ftheta lens 14 as light beam 12a to be focused, thus generating a beam spot 4 on the surface 3a of a sample with the formation of an irradiation light 6. A scattered light 7 generated by irradiation of fine particles 16 on the surface 3a with the beam spot 4 is focused with an optical fiber bundle 15 and made incident into a wavelength selection filter 17. The light passing through a filter 17 is made incident into a photoelectric converter 18 to output an electrical signal 19 corresponding to the quantity of light. Then, the scattered light alone of the irradiation light 6 due to the fine particles 16 is incident into the photoelectric converter 18 without the entry of any disturbing light 22 with the wavelength differing from that lambda into the photoelectric converter 18 even when the light 22 is incident into the optical fiber bundle 15. Thus, the inspection of the sample surface 3a can be performed without the effect of the disturbing light 22. |
