US 2026/0304584 A1Published application

Laser synchronization with target motion for euv source optimization

AssigneeKLA Corporation

InventorsPatrick Tae, Dmitry Melnik, Jian Xu

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Abstract

A broadband light source and method are disclosed. The broadband light source may include a rotatable drum at least partially coated with plasma-forming target material, a rotational actuator configured to rotate the rotatable drum, a linear actuator configured to axially translate the rotatable drum, and a laser source configured to direct pulsed illumination to a set of spots on a material-coated portion of the rotatable drum for exciting the plasma-forming target material and emitting broadband light. The broadband light source may include a control system configured to receive laser clock data of the laser source. The control system may be configured to control, in a closed loop synchronized configuration, the actuation of the rotational and linear actuators based on at least the laser clock data to selectively position a plurality of loops of the set of spots on the material-coated portion of the rotatable drum.

Claims25

Dependent claims

A broadband light source comprising:

a rotatable drum at least partially coated with plasma-forming target material;
a rotational actuator configured to rotate the rotatable drum;
a linear actuator configured to axially translate the rotatable drum in an axial direction;
a laser source configured to direct pulsed illumination to a set of spots on a material-coated portion of the rotatable drum for exciting the plasma-forming target material and emitting broadband light as the rotational actuator rotates the rotatable drum and the linear actuator translates the rotatable drum;
and
a control system, wherein the control system is configured to:
receive laser clock data of the laser source;
and
control, in a closed loop synchronized configuration, the actuation of the rotational actuator and the linear actuator based on at least the laser clock data to selectively position a plurality of loops of the set of spots on the material-coated portion of the rotatable drum,
wherein for each loop, the set of spots are positioned such that the set of spots comprise:
a first set of spots arranged in a first spiral pattern from a first end of the rotational drum to a second end of the rotational drum;
a set of second end transition spots arranged in a turn-around portion near the second end of the rotational drum;
a second set of spots arranged in a second spiral pattern from the second end of the rotational drum to the first end of the rotational drum, wherein the first set of spots and the second set of spots are interleaved such that spots from the second set of spots do not overlap with spots from the first set of spots;
and
a set of first end transition spots arranged in a turn-around portion near the first end of the rotational drum.

12 more elements

An inspection system comprising:

a broadband light source, wherein the broadband light source comprises:
a rotatable drum at least partially coated with plasma-forming target material;
a rotational actuator configured to rotate the rotatable drum;
a linear actuator configured to axially translate the rotatable drum;
a laser source configured to direct pulsed illumination to a set of spots on a material-coated portion of the rotatable drum for exciting the plasma-forming target material and emitting broadband light as the rotational actuator rotates the rotatable drum and the linear actuator translates the rotatable drum in an axial direction;
a control system, wherein the control system is configured to:
receive laser clock data of the laser source;
and
control, in a closed loop synchronized configuration, the actuation of the rotational actuator and the linear actuator based on at least the laser clock data to selectively position a plurality of loops of the set of spots on the material-coated portion of the rotatable drum,
wherein for each loop, the set of spots are positioned such that the set of spots comprise:
a first set of spots arranged in a first spiral pattern from a first end of the rotational drum to a second end of the rotational drum;
a set of second end transition spots arranged in a turn-around portion near the second end of the rotational drum;
a second set of spots arranged in a second spiral pattern from the second end of the rotational drum to the first end of the rotational drum, wherein the first set of spots and the second set of spots are interleaved such that spots from the second set of spots do not overlap with spots from the first set of spots;
and
a set of first end transition spots arranged in a turn-around portion near the first end of the rotational drum;
one or more collection optics configured to collect illumination emanated from a plasma generated in response to the excitation of the plasma-forming target material;
a set of illuminator optics configured to direct the illumination from the one or more collection optics to one or more samples disposed on a stage;
a detector;
and
a set of projection optics configured to receive illumination from a surface of the one or more samples and direct the illumination from the one or more samples to the detector.

17 more elements

Dependencies are inferred from the claim text.