Defect inspecting method and defect inspecting apparatus
View Patent ↗A defect inspecting method and apparatus for inspecting a surface state including a defect on a wafer surface, in which a polarization state of a laser beam irradiated onto the wafer surface is connected into a specified polarization state, the converted laser beam having the specified polarization state is inserted onto the wafer surface, and a scattering light occurring from an irradiated region where the laser beam having the specified polarization state is irradiated, is separated into a first scattering light occurring due to a defect on the wafer and a second scattering light occurring due to a surface roughness on the wafer. An optical element for optical path division separates the first and second scattering lights approximately at the same time.
1. A defect inspecting method of inspecting a surface state including a defect on a wafer surface, the method comprises the steps of:
adjusting a polarization axis of a polarization filter;
irradiating a laser beam onto the wafer surface;
detecting a scattering light occurring from an irradiated region on the wafer surface via the adjusted polarization filter; and
separating a detected signal of the detected scattering light into a defect signal and a haze signal.
2. The defect inspecting method according to claim 1 , wherein the polarization filter is configured to enable or disable a polarization axis rotation or filtering.
3. The defect inspecting method according to claim 1 , wherein a polarization axis of the polarization filter is adjusted to a first polarization axis for defect measurement or a second polarization axis for haze measurement.
4. The defect inspecting method according to claim 1 , wherein the polarization filter comprises segments each of which has an individual polarization axis.
5. The defect inspecting method according to claim 4 , wherein the polarization axis varies one-dimensionally or two-dimensionally.
6. The defect inspecting method according to claim 1 , wherein the detected scattering light is separated by a divider including one of amplitude division, wavelength division, and polarization division.
7. The defect inspecting method according to claim 1 , wherein the laser beam is irradiated from a plurality of light sources having different wavelengths.
8. The defect inspecting method according to claim 1 , wherein the laser beam is irradiated approximately vertically onto the wafer surface.
9. The defect inspecting method according to claim 1 , wherein the laser beam is irradiated obliquely onto the wafer surface.
10. A defect inspecting apparatus for inspecting a surface state including a defect on a wafer surface, the apparatus comprising:
an irradiator which irradiates a laser beam onto the wafer surface;
a polarization filter;
a filter which adjusts a polarization axis of said polarization filter;
a detector which detects a scattering light occurring from an irradiated region on the wafer surface via the polarization filter; and
a separator which separates a detected signal the detected scattering light into a defect signal and a haze signal.
11. The defect inspecting apparatus according to claim 10 , wherein the polarization filter is configured to enable or disable a polarization axis rotation or filtering.
12. The defect inspecting apparatus according to claim 11 , wherein a polarization axis of the polarization filter is adjusted for defect measurement and for haze measurement.
13. The defect inspecting apparatus according to claim 11 , wherein the polarization filter comprises segments each of which has an individual polarization axis.
14. The defect inspecting apparatus according to claim 13 , wherein said polarization filter varies one-dimensionally or two-dimensionally.
15. The defect inspecting apparatus according to claim 11 , further comprising a separator which separates the scattering light by a divider including one of amplitude division, wavelength division, and polarization division.
16. The defect inspecting apparatus according to claim 11 , wherein the laser beam is irradiated from a plurality of light sources having different wavelengths.
17. The defect inspecting apparatus according to claim 10 , wherein a polarization axis of the polarization filter is adjusted for defect measurement and for haze measurement.
18. The defect inspecting apparatus according to claim 10 , wherein the laser beam is irradiated onto the wafer surface.
19. The defect inspecting apparatus according to claim 10 , wherein a laser beam is irradiated obliquely onto the wafer surface.