EUV Light Source Calibration via Unified Coordinate System
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Solution Overview
Problem
Existing EUV light sources require complex and time-consuming calibration procedures to align components, and lack a unified coordinate system, leading to inefficiencies and errors in calibration and operation.
Innovation Solution
A metrology system that includes a light beam metrology apparatus, a target metrology apparatus, and a control apparatus, which senses aspects of the amplified light beam and measures properties of the target to determine a reference calibration state, allowing for precise calibration and control of the EUV light source.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional calibration procedures are used to align components in an EUV light source, then alignment accuracy can be achieved, but the calibration process becomes complex and time-consuming
Solution Approach 1:
The patent combines multiple separate calibration procedures into a single unified calibration process. By integrating the coordinate system definitions and alignment procedures for different components (laser beam, target, plasma) into one unified calibration routine, the system achieves comprehensive alignment accuracy while reducing overall calibration complexity and time requirements.
Solution Approach 2:
The patent creates a universal calibration system that serves multiple functions simultaneously. The unified coordinate system and calibration procedure can calibrate different components (laser steering mirrors, target positioning, plasma diagnostics) using a common reference framework, eliminating the need for separate calibration procedures for each component.
2Measurement precision
If traditional calibration procedures are used to align components in an EUV light source, then alignment accuracy can be achieved, but the calibration time increases significantly
Solution Approach 1:
The patent establishes preliminary unified coordinate systems for all components before the actual calibration process begins. By pre-defining the coordinate frameworks and reference points for laser beams, targets, and plasma regions, the system eliminates the need for time-consuming iterative alignment procedures during calibration, significantly reducing calibration time while maintaining accuracy.
Solution Approach 2:
The patent implements feedback mechanisms where calibration measurements from one component inform and adjust the calibration of other components. The unified calibration system uses real-time feedback from coordinate system transformations and alignment measurements to rapidly converge on accurate positioning, reducing the number of calibration iterations required.
3Ease of operation
If separate coordinate systems are used for different components, then each component can be calibrated independently, but errors accumulate and alignment precision deteriorates
Solution Approach 1:
The patent merges separate component coordinate systems into a unified coordinate system that encompasses all components (laser beam, target, plasma). This unified framework allows independent calibration of each component while maintaining precise relative alignment through consistent coordinate transformations, eliminating error accumulation that occurs with separate coordinate systems.
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
The system enables rapid and accurate calibration of the EUV light source, reducing downtime and improving the efficiency and quality of EUV light production, while also providing a unified coordinate system for improved alignment and operation.
Implementation Method 1
converting a material that has an element, for example, xenon, lithium, or tin, with an emission line in the EUV range in a plasma state. In one such method, often termed laser produced plasma (LPP), the required plasma can be produced by irradiating a target material
Implementation Method 2
the plasma can be produced by irradiating a target material, for example, in the form of a droplet, plate, tape, stream, or cluster of material, with an amplified light beam that can be referred to as a drive laser
Implementation Method 3
The light beam metrology apparatus is configured to sense one or more aspects of an amplified light beam and to make adjustments to the amplified light beam based on the sensed one or more aspects
Data Source
AI summary
A metrology system includes a light beam metrology apparatus configured to sense one or more aspects of an amplified light beam and to make adjustments to the amplified light beam based on the sensed one or more aspects; a target metrology apparatus configured to measure one or more properties of a modified target after a target has interacted with the amplified light beam, and to determine a moment when the modified target achieves a reference calibration state; and a control apparatus configured to: receive the reference calibration state and the moment at which the reference calibration state is achieved from the target metrology apparatus; determine a light beam calibration state of the amplified light beam based on the received reference calibration state and the moment at which the reference calibration state is achieved; and provide the light beam calibration state to the light beam metrology apparatus.