US 2002/0162979 A1 · Optically scanning apparatus and defect inspection system

Abstract

An optically scanning apparatus and defect inspection system able to detect a defect with a high resolution and able to greatly shorten the inspection time. An radiation beam generated from a light source is converted to a light beam array of an m×n matrix by a two-dimensional diffraction grating. The light beams of the light beam array are focused into micro spots by an objective lens and projected on a sample. Therefore, a two-dimensional light spot array of an m×n matrix is formed on a sample. The sample stage rotates and moves rectilinearly in an r direction, so the sample surface is scanned by the m×n matrix of light spots. As a result, the sample surface is spirally scanned by a light beam of a belt shape of the scan width, so can be scanned at a high speed. Further, the beams reflected by the sample surface are received by light receiving elements separated by light blocking members, so a confocal optical system is formed and as a result the resolution of detection of defects becomes much higher.

Claims29

Dependent claims

An optically scanning apparatus comprising:

a light source for emitting a radiation beam;
a two-dimensional diffraction grating for converting said radiation beam into a two-dimensional array of light beams arranged in an m×n matrix, where m and n are natural numbers or 2 or more;
an objective lens for focusing the m×n number of light beams into spots to form an array of light spots arranged in an m×n matrix on a sample to be inspected;
a photosensor having an array of light receiving elements arranged in an m′×n′ (m′ and n′ being natural numbers of 2 or more) matrix, the light receiving elements separated from each other and receiving beams reflected at the sample surface;
a sample stage for supporting a sample to be inspected for defects;
and
a stage drive system having a rotational drive device for rotating said sample stage and a rectilinear movement device for moving the sample stage along an axis perpendicular to the rotational axis and making said sample stage move relative to said light spot array;
wherein the sample surface is scanned by the two-dimensional light spot array arranged in an m×n matrix by making the sample and light spot array move relative to each other.

5 more elements

A defect inspection apparatus comprising:

a light source for emitting a radiation beam;
a two-dimensional diffraction grating for converting said radiation beam into a two-dimensional array of light beams arranged in an m×n matrix, where m and n are natural numbers of 2 or more;
an objective lens for focusing the m×n number of light beams into spots to form an array of light spots arranged in an m×n matrix on a sample to be inspected;
a photosensor having an array of light receiving elements arranged in an m′×n′ (m′ and n′ being natural numbers of 2 or more) matrix, the light receiving elements separated from each other and receiving beams reflected at the sample surface;
a sample stage for supporting a sample to be inspected for defects;
and
a stage drive system having a rotational drive device for rotating said sample stage and a rectilinear movement device for moving the sample stage along an axis perpendicular to the rotational axis and making said sample stage move relative to said light spot array;
and
a defect detection system for detecting a defect present on a surface region of a sample based on an output signal from a light receiving element of said photosensor.

6 more elements

Dependencies are inferred from the claim text.

Optically scanning apparatus and defect inspection system

Life of this patent

Optically scanning apparatus and defect inspection system

Life of this patent

Abstract

Claims29