EUV Light Generation Target Position Detection

Solution Overview

Problem

Existing EUV light generation systems face challenges in accurately detecting the position of the target due to the presence of dark parts or background light distribution changes, which can lead to misalignment and failure in generating EUV light.

Innovation Solution

The EUV light generation apparatus includes a processor that creates a background image using a second target image where the target position does not overlap, corrects the first target image to remove background light, and detects the target position based on the background-corrected image.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the target position is detected using conventional imaging methods, then the detection process is simple, but the detection precision deteriorates due to dark parts and background light distribution changes

Engineering Contradiction:

Improvetarget position detection precisionVSAvoidimage processing complexity

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The system performs preliminary actions by capturing a background image before the target enters the detection region, and capturing another image after the target has moved to a position where it does not overlap with the first image. These preliminary images are used to create a background-corrected image that compensates for dark parts and background light distribution changes, enabling accurate target position detection without requiring complex real-time processing during target detection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The background-corrected image serves as an intermediary that mediates between the raw images and the final target position detection. By subtracting the background image from the second image (where the target is not present), the system creates a corrected background model that is then used to accurately identify the target position in subsequent images, effectively separating the target signal from background interference.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the background light distribution changes are not corrected, then the imaging process is simple, but the target position detection becomes inaccurate leading to misalignment

Engineering Contradiction:

ImproveEUV light generation reliabilityVSAvoidimage processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The system performs preliminary actions by capturing a background image before the target enters the detection region, and capturing another image after the target has moved to a position where it does not overlap with the first image. These preliminary images are used to create a background-corrected image that compensates for dark parts and background light distribution changes, enabling accurate target position detection without requiring complex real-time processing during target detection.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The system uses the background-corrected image as feedback to continuously monitor and adjust the target position detection. By comparing the background-corrected image with subsequent images, the system can detect changes in background light distribution and adjust the detection algorithm accordingly, ensuring reliable EUV light generation through accurate target positioning.

Inventive Principle:

Principle #23Feedback

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution enables accurate detection of the target position even when dark parts are present, ensuring reliable EUV light generation and addressing changes in the background light distribution during operation.

Implementation Method 1

a target imaging device configured to create a first target image by imaging a region including the target and a second target image by imaging the region at a timing at which a position of the target in the second target image does not overlap with a position thereof in the first target image

Methodology Applied

Scientific EffectImaging: Photography

Data Source

PatentUS20250164889A1EUV light generation apparatus and electronic device manufacturing method

Publication Date: 2025.05.22 GIGAPHOTON INC

AI summary

An EUV light generation apparatus according to an aspect of the present disclosure includes a chamber, a target supply device configured to supply a target into the chamber, a target imaging device configured to create a first target image by imaging a region including the target and a second target image by imaging the region at a timing at which a position of the target in the second target image does not overlap with a position thereof in the first target image, and a processor configured to create a background image using at least the second target image, creating a background corrected image by correcting the first target image, and detecting a position of the target based on the background corrected image.