Surface inspection apparatus
First Claim
1. A surface inspection apparatus comprising:
- a light source portion for emitting a light wave of a first wavelength and a light wave of a second wavelength;
a first irradiating optical system for directing a light beam of a first wavelength onto the surface of an inspected body in a first angle of irradiation;
a second irradiating optical system for directing a light beam of a second wavelength onto the surface of the inspected body in a second angle of irradiation different from the first angle of irradiation and at the same time said light beam of the first wavelength is directed by the first irradiating optical system;
a first photosensing optical system for sensing in a first photosensing direction scattered light from the surface of the inspected body irradiated by said first irradiating optical system;
a second photosensing optical system for sensing in a second photosensing direction scattered light from the surface of the inspected body irradiated by said second irradiating optical system;
a first photosensing portion for converting the scattered light of the first wavelength sensed by said first photosensing optical system into a first sensed-light signal;
a second photosensing portion for converting the scattered light of the second wavelength sensed by said first photosensing optical system into a second sensed-light signal;
a third photosensing portion for converting the scattered light of the first wavelength sensed by said second photosensing optical system into a third sensed-light signal;
a fourth photosensing portion for converting the scattered light of the second wavelength sensed by said second photosensing optical system into a fourth sensed-light signal;
a displacement portion for displacing said inspected body and the light beams emitted from said irradiating optical systems relative to each other; and
a signal processing portion for discriminating inspected objects on the basis of said first to fourth sensed-light optical signals.
1 Assignment
0 Petitions
Accused Products
Abstract
A wafer surface inspection apparatus comprises a light source, an optical system for focusing the light beams from the light source onto the wafer surface, a scanning means for scanning the focused point over a predetermined range on the wafer surface, a photo detector including an photoelectric converter for sensing scattered light from the focused point, and a signal detector for detecting signals from the photo detector, in which the light source is a light source for emitting two different wavelengths, the optical system is adapted to focus the light beams of the two wavelengths on one and the same point on the wafer surface, and the photo detector is adapted to sense the two wavelengths separately, and further comprises a discriminating portion for discriminating between a foreign matter or a scratch on the wafer surface and a recess in a spot form existing on the wafer surface by utilizing outputs from the signal detector.
-
Citations
12 Claims
-
1. A surface inspection apparatus comprising:
-
a light source portion for emitting a light wave of a first wavelength and a light wave of a second wavelength; a first irradiating optical system for directing a light beam of a first wavelength onto the surface of an inspected body in a first angle of irradiation; a second irradiating optical system for directing a light beam of a second wavelength onto the surface of the inspected body in a second angle of irradiation different from the first angle of irradiation and at the same time said light beam of the first wavelength is directed by the first irradiating optical system; a first photosensing optical system for sensing in a first photosensing direction scattered light from the surface of the inspected body irradiated by said first irradiating optical system; a second photosensing optical system for sensing in a second photosensing direction scattered light from the surface of the inspected body irradiated by said second irradiating optical system; a first photosensing portion for converting the scattered light of the first wavelength sensed by said first photosensing optical system into a first sensed-light signal; a second photosensing portion for converting the scattered light of the second wavelength sensed by said first photosensing optical system into a second sensed-light signal; a third photosensing portion for converting the scattered light of the first wavelength sensed by said second photosensing optical system into a third sensed-light signal; a fourth photosensing portion for converting the scattered light of the second wavelength sensed by said second photosensing optical system into a fourth sensed-light signal; a displacement portion for displacing said inspected body and the light beams emitted from said irradiating optical systems relative to each other; and a signal processing portion for discriminating inspected objects on the basis of said first to fourth sensed-light optical signals. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
-
-
9. A wafer surface inspecting method comprising the steps of:
-
focusing light beams emitted from a light source on the surface of a wafer; sensing scattered light from the focused point with a photoelectric converter while the focused point is scanned; and inspecting foreign matters and flaws on the wafer surface through detection of signals from said photoelectric converter, wherein irradiating light beams of two wavelengths are focused on one and the same point in different angles of incidence and at the same time scattered light beams from the focused point are photoelectrically converted separately for each of the two wavelengths, and discriminating a foreign matter or flaw on the wafer surface and a recess in a spot form existing on the wafer surface from each other by utilizing differences in intensity of the signals. - View Dependent Claims (10)
-
-
11. A wafer surface inspection apparatus comprising:
-
a light source; an optical system for focusing light beams from said light source on a wafer surface; a photosensing portion including a photoelectric converter for sensing scattered light beams from a focused point; a signal detector for detecting signals from said photosensing portion, wherein said light source is a light source of two different wavelengths and said optical system is adapted to focus light beams of two wavelengths on said focussed point on the wafer surface in different angles of incidence and at the same time; and a discriminating circuit for discriminating between a foreign matter or flaw on the wafer surface and a recess in a spot form existing on the wafer surface by utilizing outputs from said signal detector. - View Dependent Claims (12)
-
Specification