Multi beam scanning with bright/dark field imaging
AssigneeApplied Materials, Inc.
InventorSilviu Reinhorn
Life of this patent
Estimating the term…
Abstract
Bright and dark field imaging operations in an optical inspection system occur along substantially the same optical path using the same light source by producing either a circular or an annular laser beam. Multiple beam splitting is achieved through the use of a diffractive optical element having uniform diffraction efficiency. A confocal arrangement for bright field and dark field imaging can be applied with multiple beam scanning for suppressing the signal from under-layers. A scan direction not perpendicular to the direction of movement of a target provides for improved die-to-die comparisons.
Claims59
An optical inspection system, comprising:
- a light source outputting an annular beam;
- an objective lens focusing the annular beam at a target;
- and
- a detector receiving light scattered from the target, through the objective lens.
An optical inspection system, comprising:
- a light source outputting a single beam;
- a scanner scanning the single beam along a line in a given scanning direction to provide a scanned single beam;
- and
- a multiple beam splitter producing multiple beams of substantially identical intensity from the scanned single beam.
An optical inspection system, comprising:
- a light source outputting a beam;
- and
- a scanner scanning the beam in a beam spot across a target, the target being movable in a target movement direction;
- wherein the beam has a scanning direction not perpendicular to the target movement direction.
An optical inspection system, comprising:
- a light source outputting a beam;
- a confocal optical arrangement;
- and
- optics for focusing the beam at a target and directing captured light to a detector through the confocal optical arrangement.
A method for optical inspection, comprising:
- generating an annular light beam;
- scanning the annular beam along a line in a given scanning direction to provide a scanned single beam;
- and
- splitting the scanned single beam to provide multiple beams of substantially identical intensity from the scanned single beam;
- and
- detecting signals generated from an interaction between the plurality of multiple beams and an inspected object.
An optical inspection system, comprising:
- a light source providing a beam of light through a pupil;
- a multiple beam splitter receiving the light through the pupil;
- a scanner receiving the multiple beams and providing scanned multiple beams;
- a beam splitter receiving the scanned multiple beams and illuminating a target through an objective lens;
- the objective lens collecting light returned back from the illuminated target and passing the collected light through the beam splitter to an imaging lens;
- the imaging lens receiving the light passing through the beam splitter and focusing the light to a bright field channel detector.
An optical inspection system, comprising:
- a light source providing a beam of light;
- a scanner receiving the light through a first beam splitter and providing scanned light;
- a second beam splitter receiving the scanned light through a scan lens, and illuminating a target through an objective lens;
- the objective lens collecting light returned back from the illuminated target and passing the collected light to the second beam splitter;
- the second beam splitter providing part of the collected light, as a returned light signal, back through the scan lens and scanner to the first beam splitter;
- the first beam splitter deflecting the returned light signal through a focusing lens and a pinhole;
- and
- one or more detectors receiving the light through the pinhole.
An optical inspection method, comprising:
- outputting an annular beam from a light source;
- focusing the annular beam at a target;
- and detecting light scattered from the target.
An optical inspection method, comprising:
- outputting a single beam;
- scanning the single beam along a line in a given scanning direction to provide a scanned single beam;
- and
- producing multiple beams of substantially identical intensity from the scanned single beam.
An optical inspection method, comprising:
- outputting a beam;
- and
- scanning the beam in a beam spot across a target, the target being movable in a target movement direction;
- wherein the beam has a scanning direction not perpendicular to the target movement direction.
An optical inspection method, comprising:
- outputting a beam;
- and
- focusing the beam at a target;
- and
- directing captured light to a detector through a confocal optical arrangement.
An optical inspection method, comprising:
- providing a beam of light;
- providing scanned multiple beams from the beam of light;
- illuminating a target, with the scanned multiple beams, through an objective lens;
- collecting light, returned back from the illuminated target, with the objective lens;
- passing the collected light through to an imaging lens;
- focusing the light of the imaging lens to a bright field channel detector.
An optical inspection method, comprising:
- providing a beam of light;
- passing the beam of light through a first beam splitter;
- scanning the light received through a first beam splitter to provide scanned light;
- passing the scanned light through a scan lens and a second beam splitter, and illuminating a target through an objective lens;
- collecting light returned back from the illuminated target;
- passing the collected light to the second beam splitter;
- providing part of the collected light, as a returned light signal, back through the scan lens and scanner to the first beam splitter;
- deflecting the returned light signal, with the first beam splitter, through a focusing lens and a pinhole;
- and
- receiving the light through the pinhole using one or more detectors.
Dependencies are inferred from the claim text.