Projection Exposure Aberration Mapping With Adaptive Measuring Points

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Solution Overview

Problem

Existing projection exposure systems face challenges in maintaining high imaging quality and throughput due to varying imaging aberrations across the image field, which are costly and time-consuming to measure and correct.

Innovation Solution

A method and system for optimizing measuring point distributions to efficiently gather aberration information, using customized metrology patterns that account for individual system variations and use cases, allowing for precise control of manipulators to correct aberrations while minimizing measurement time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If comprehensive aberration measurements are performed across the entire image field, then imaging quality is improved, but measurement time and cost increase

Engineering Contradiction:
Improveimaging qualityVSAvoidmeasurement time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The image field is divided into multiple segments with different measuring point distributions assigned to different field regions. High-density measuring points are placed in regions requiring precise aberration correction, while low-density distributions are used in regions with lower requirements, thereby reducing overall measurement time while maintaining imaging quality where needed

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different measuring point densities are applied to different local regions of the image field based on their specific aberration characteristics and correction requirements. This localized approach ensures high measurement precision in critical areas while reducing measurement burden in less critical areas

Inventive Principle:
Principle #3Local quality

2Ease of operation

If standardized measuring point distributions are used, then measurement process is simplified, but individual system variations cannot be adequately addressed

Engineering Contradiction:
Improvemeasurement processVSAvoidsystem variation accommodation
Core Design Contradiction:
Ease of operationVSAdaptability or versatility

Solution Approach 1:

The measuring point distribution is made dynamic and adaptive rather than static and standardized. The system automatically determines optimal measuring point locations based on real-time aberration measurements and system characteristics, allowing the measurement strategy to adapt to individual system variations while maintaining operational simplicity

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The measurement system performs self-optimization by automatically determining its own measuring point distribution based on measured aberration patterns. The system uses initial measurements to identify problematic regions and automatically concentrates measurement resources there, eliminating the need for external optimization input

Inventive Principle:
Principle #25Self-service

Data Source

PatentUS12601978B2Method of setting up a projection exposure system, a projection exposure method and a projection exposure system for microlithography
Publication Date: 2026.04.14 CARL ZEISS SMT GMBH
  • US12601978B2 patent drawing
  • US12601978B2 patent drawing
  • US12601978B2 patent drawing

AI summary

A measuring system (MS) configured to measure a projection radiation property representing an aberration level at a plurality of spaced apart measuring points distributed in the image field; and an operating control system with at least one manipulator operatively connected to an optical element of a projection exposure system to modify imaging properties of the projection exposure system based on measurement results generated by the measuring system. In a measuring point distribution calculation (MPDC), a measuring point distribution defining a number and positions of measuring points is used. The MPDC is performed under boundary conditions representing at least: (i) manipulation capacities of the operating control system; (ii) measuring capacities of the measuring system; and (iii) predefined use case scenarios defining a set of representative use cases. Each use case corresponds to a specific aberration pattern generated by the projection exposure system under a predefined set of use conditions.