Defect inspection method and its device
First Claim
1. A defect inspection device, comprising:
- a table unit on which a target sample to be inspected is mounted;
an illumination optical system unit configured to obliquely illuminate the sample mounted on the table unit;
a detecting optical system unit which condenses scattered light generated from the sample on which illumination light is obliquely irradiated by the illumination light optical system unit, and detects an image on a surface of the sample using the scattered light;
an image processing unit configured to process a signal obtained by detecting the image on the surface of the sample using the scattered light by the detecting optical system unit, to extract defect candidates on the surface of the sample; and
a control unit which controls the table unit, the illumination optical system unit, the detecting optical system unit, and the image processing unit,wherein the illumination optical system unit includesa laser light source which emits a laser beam;
a beam expander which expands a diameter of the laser beam;
an anamorphic optical unit which controls a size of the laser beam in a particular direction;
a cylindrical optical unit which condenses the laser beam passed through the anamorphic optical unit in one direction and forms a linearly condensed light image as an intermediate image; and
a relay lens unit which forms the linearly condensed light image on a surface of the specimen mounted on the table unit to illuminate a linear region on the specimen,wherein a polarization condition of the laser beam passing through the anamorphic optical unit and the cylindrical optical unit is a specific linearly polarized condition,wherein optical coatings are applied to surfaces of a cylindrical lens of the cylindrical optical unit, said optical coatings corresponding to the polarization state of the laser beam to reduce power loss of the laser beam, andwherein the relay lens unit includes a polarization control element which controls polarization condition of the laser beam illuminating the specimen.
2 Assignments
0 Petitions
Accused Products
Abstract
To increase the illumination efficiency by facilitating the change of the incident angle of illumination light with a narrow illumination width according to an inspection object and enabling an illumination region to be effectively irradiated with light, provided is a defect inspection method for obliquely irradiating a sample mounted on a table that is moving continuously in one direction with illumination light, collecting scattered light from the sample obliquely irradiated with the illumination light, detecting an image of the surface of the sample formed by the scattered light, processing a signal obtained by detecting the image formed by the scattered light, and extracting a defect candidate, wherein the oblique irradiation of the light is implemented by linearly collecting light emitted from a light source, and obliquely projecting the collected light onto the surface of the sample, thereby illuminating a linear region on the surface of the sample.
12 Citations
20 Claims
-
1. A defect inspection device, comprising:
-
a table unit on which a target sample to be inspected is mounted; an illumination optical system unit configured to obliquely illuminate the sample mounted on the table unit; a detecting optical system unit which condenses scattered light generated from the sample on which illumination light is obliquely irradiated by the illumination light optical system unit, and detects an image on a surface of the sample using the scattered light; an image processing unit configured to process a signal obtained by detecting the image on the surface of the sample using the scattered light by the detecting optical system unit, to extract defect candidates on the surface of the sample; and a control unit which controls the table unit, the illumination optical system unit, the detecting optical system unit, and the image processing unit, wherein the illumination optical system unit includes a laser light source which emits a laser beam; a beam expander which expands a diameter of the laser beam; an anamorphic optical unit which controls a size of the laser beam in a particular direction; a cylindrical optical unit which condenses the laser beam passed through the anamorphic optical unit in one direction and forms a linearly condensed light image as an intermediate image; and a relay lens unit which forms the linearly condensed light image on a surface of the specimen mounted on the table unit to illuminate a linear region on the specimen, wherein a polarization condition of the laser beam passing through the anamorphic optical unit and the cylindrical optical unit is a specific linearly polarized condition, wherein optical coatings are applied to surfaces of a cylindrical lens of the cylindrical optical unit, said optical coatings corresponding to the polarization state of the laser beam to reduce power loss of the laser beam, and wherein the relay lens unit includes a polarization control element which controls polarization condition of the laser beam illuminating the specimen. - View Dependent Claims (2, 3, 4, 5, 6, 7, 15, 16, 17)
-
-
8. A defect inspection method, comprising the steps of:
-
irradiating illumination light obliquely onto a sample mounted on a table which is continuously moved in one direction; detecting an image on a surface of the sample using scattered light, by condensing the scattered light generated on the sample onto which the illumination light is obliquely irradiated; and processing a signal obtained by detecting the image on the surface of the sample using the scattered light to extract defect candidates on the surface of the sample, wherein said irradiating the illumination light obliquely onto the sample includes emitting a laser beam from a laser light source; expanding a diameter of the laser beam with a beam expander; controlling a size of the laser beam in a particular direction with an anamorphic optical unit; condensing the laser beam passed through the anamorphic optical unit in one direction and forming a linearly condensed light image as an intermediate image with a cylindrical optical unit; and forming the linearly condensed light image on a surface of the specimen mounted on the table to illuminate a linear region on the specimen with a relay lens unit, wherein a polarization condition of the laser beam passing through the anamorphic optical unit and the cylindrical optical unit is a specific linearly polarized condition, wherein power loss of the laser beam is reduced by optical coatings corresponding to a polarization state of the laser beam, the optical coatings being applied to surfaces of a cylindrical lens of the cylindrical optical unit, and wherein a polarization condition of the laser beam illuminating the specimen is controlled by a polarization control element included in the relay lens unit. - View Dependent Claims (9, 10, 11, 12, 13, 14, 18, 19, 20)
-
Specification