JP2007528607A5

JP2007528607A5 -

Info

Publication number: JP2007528607A5
Application number: JP2007502838A
Authority: JP
Filing date: 2005-02-24
Publication date: 2008-04-10
Anticipated expiration: 2025-02-24

Claims

A laser generated plasma (LPP) extreme ultraviolet (EUV) light source control system comprising a target delivery system adapted to deliver a plasma initiation target and an EUV light focusing optics having a focal point defining a desired plasma initiation site, ,
Target tracking and feedback system,
Including
The target tracking and feedback system includes:
At least one imager that provides as an output an image of the target stream path, and an error in the position of the target stream path in at least one axis substantially perpendicular to the target stream path from the desired stream path intersecting the desired plasma start site A stream path error detector for detecting
including,
A system characterized by that.

At least one target crossing detector aiming at the target path and detecting the passage of the target through a selected spot in the target path;
The device of claim 1 further comprising:

The at least one target crossing detector is at least a first target crossing detector and a second target crossing detector;
The device of claim 2 further comprising:

A drive laser output pulse utilizes the output of the cross-target detector to intersect the plasma start target at a selected plasma start site at about its closest approach to the desired plasma start site along the target path. Drive laser trigger mechanism to determine the timing of the drive laser trigger,
The device of claim 2 further comprising:

A plasma start detector for aiming at the target path and detecting the position of the plasma start site along the target path for each target;
The device of claim 1 further comprising:

An intermediate focus illuminator that illuminates the aperture formed in the intermediate focus and images the aperture on the at least one imaging device;
The device of claim 1 further comprising:

The at least one imaging device is at least two imaging devices, each based on an analysis of an image at a respective one of the at least two imaging devices, and the target from a vertical central axis of the intermediate focus image Provide error signals related to path separation,
The device of claim 6 further comprising:

Target delivery feedback and control system,
Further including
The target delivery feedback and control system includes:
A target delivery unit;
At least in the axis corresponding to the first displacement error signal derived from the analysis of the image in the first imaging device and at least in the second displacement error signal derived from the analysis of the image in the second imaging device. A target delivery displacement control mechanism for displacing the target delivery mechanism in a corresponding axis;
including,
The device according to claim 7.

EUV output light energy detection mechanism,
Further including
The EUV output light energy detection mechanism includes:
A plurality of EUV light energy detectors arranged to measure EUV light energy reaching said intermediate focus, each providing an output signal representing the amount of EUV light energy detected by a respective detector;
An EUV light energy error signal generator that receives the output of each EUV light energy detector and determines an EUV light energy error signal based on a comparison of the respective values of the output signals of the respective EUV light energy detectors; ,
including,
The device according to claim 8.

Start site error detection mechanism,
Further including
The start site error detection mechanism includes:
One of the at least two imaging devices for supplying image data;
Including
A separation in the first axis of the actual plasma start site from a desired plasma start site based on an analysis of the image data in the respective one of the at least two imaging devices from the image data; and in the respective imaging device Determining a first error signal associated with a separation in a second axis perpendicular to the first axis of the plasma start site from a horizontal central axis of the image at the intermediate focus based on an analysis of the image; Can
The device according to claim 9.

Laser-produced plasma (LPP) extreme ultraviolet (EUV) light comprising using a control system that includes a target delivery system for delivering a moving plasma forming target and an EUV light collection optics having a focal point that defines a desired plasma start site A method for generating
Using target tracking and feedback methods;
Including
The method
Using at least one imaging device to prepare an image of the target stream path;
Using a stream path error detector to detect an error in the position of the target stream path in at least one axis substantially perpendicular to the target stream path from the desired stream path intersecting the desired plasma start site;
including,
A method characterized by that.