Lithography Mark Position Determination Using Layer Patterns

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The increasing demand for improved overlay accuracy in device manufacturing, particularly with high integration and miniaturization, is hindered by the need for accurate alignment of a large number of alignment marks on substrates, which restricts the miniaturization and reduction of alignment marks, degrading measurement accuracy and increasing measurement time.

Innovation Solution

A method for determining the position of a mark on a substrate using both a first pattern in a first layer and a second pattern in a second layer, involving provisional position determination based on image data and relative position information to enable accurate alignment even when using overlay inspection marks as alignment marks.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If overlay inspection marks are used as alignment marks, then the pattern region is restricted and measurement accuracy degrades, but the number of marks can be reduced

Engineering Contradiction:

Improvenumber of alignment marksVSAvoidmeasurement accuracy

Core Design Contradiction:

Quantity of substanceVSMeasurement precision

Solution Approach 1:

The patent applies preliminary action by pre-acquiring relative position information between the first and second patterns before performing alignment measurement. This pre-acquired information is stored and used during the alignment process to compensate for the restricted pattern region, enabling accurate position determination even when using overlay inspection marks that occupy the same region

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary approach by using relative position information as a mediator between the two patterns. Instead of directly measuring the position of overlay inspection marks which have restricted pattern regions, the system uses the pre-acquired relative position relationship between first and second patterns to indirectly determine the mark position, thus maintaining measurement accuracy

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If overlay inspection marks are used as alignment marks, then the number of marks can be reduced, but measurement time increases

Engineering Contradiction:

Improvenumber of alignment marksVSAvoidmeasurement time

Core Design Contradiction:

Quantity of substanceVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-acquiring and storing relative position information between patterns before the actual alignment measurement. This preparation work is done in advance, allowing the alignment process to proceed more quickly by utilizing the pre-computed relative position data rather than calculating it during the measurement phase

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses partial action by acquiring relative position information for specific pattern pairs in advance, rather than performing complete position calculations for all marks during measurement. This selective pre-processing reduces the computational burden during the actual measurement phase, thereby reducing measurement time

Inventive Principle:

Principle #16Partial or excessive action

3Measurement precision

If a large number of alignment marks are arranged on the substrate, then measurement accuracy can be maintained, but miniaturization and reduction of marks are restricted

Engineering Contradiction:

Improvemeasurement accuracyVSAvoidchip yield

Core Design Contradiction:

Measurement precisionVSProductivity

Solution Approach 1:

The patent applies preliminary action by pre-acquiring relative position information between patterns before alignment measurement. This allows the system to maintain high measurement accuracy with fewer marks by utilizing the pre-computed positional relationships, thereby enabling miniaturization and improving chip yield

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent uses a copying approach by utilizing the relative position relationship between first and second patterns as a reference model. This relative position information serves as a template that can be applied to determine mark positions without requiring multiple physical marks, thus maintaining accuracy while reducing mark quantity and enabling miniaturization

Inventive Principle:

Principle #26Copying

Data Source

PatentUS12092967B2Method of determining position of mark, lithography method, exposure apparatus, and article manufacturing method

Publication Date: 2024.09.17 CANON KK

AI summary

A method of determining a position of a mark including a first pattern arranged in a first layer of a substrate and a second pattern arranged in a second layer of the substrate, includes determining information concerning the position of the mark as provisional position information based on an image of the mark, acquiring relative position information indicating a relative position between the first pattern and the second pattern, and determining the position of the mark based on the provisional position information and the relative position information.