Reference Pattern Module for Overlay Error Measurement
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Solution Overview
Problem
The semiconductor industry faces challenges in precisely determining overlay errors between photo resist layout patterns and underlying layout patterns during lithography operations, especially as it advances to nanometer technology process nodes, requiring an efficient method to ensure accurate alignment and minimize errors.
Innovation Solution
The implementation of an overlay measurement pattern system using a reference pattern module, such as a liquid crystal display panel, which generates reference patterns to overlap with overlay measurement patterns on a substrate, allowing for the determination of overlay errors through diffracted light analysis, thereby avoiding direct overlap and multiple overlay measurement patterns on each layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple overlay measurement patterns are placed on each layer to determine overlay errors, then measurement precision is improved, but device complexity and manufacturing complexity increase
Solution Approach 1:
A reference pattern module is introduced as an intermediary component that contains multiple reference patterns. This module is positioned over the substrate and moved relative to it to enable overlay error measurement between different layers without requiring multiple measurement patterns to be directly formed on each layer, thereby reducing manufacturing complexity while maintaining measurement precision
Solution Approach 2:
Instead of forming multiple overlay measurement patterns directly on each layer of the substrate, the patent uses reference patterns that replicate the overlay measurement function. These reference patterns are created on a separate reference pattern module, which is then positioned over the substrate. This copying approach reduces the complexity of forming patterns on multiple layers while enabling precise overlay error measurement
2Measurement precision
If overlay measurement patterns are directly formed on each layer, then measurement precision is improved, but ease of manufacture deteriorates
Solution Approach 1:
The reference pattern module serves as an intermediary that consolidates multiple reference patterns in a single component. This module is positioned over the substrate and moved relative to it to enable overlay error measurement between different layers, eliminating the need to form multiple measurement patterns directly on each layer and thereby improving ease of manufacture while maintaining measurement precision
Solution Approach 2:
The patent creates reference patterns that copy the overlay measurement function on a separate reference pattern module rather than forming them directly on each layer of the substrate. This copying approach simplifies the manufacturing process by requiring pattern formation in only one location (the reference pattern module) rather than across multiple layers, while still enabling precise overlay error measurement
3Measurement precision
If direct overlap of overlay measurement patterns is used, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The reference pattern module acts as an intermediary that contains multiple reference patterns arranged in a controlled manner. This module is positioned over the substrate and moved relative to it to enable overlay error measurement between different layers, providing a simplified and controlled approach to pattern arrangement that reduces device complexity while maintaining measurement precision
Solution Approach 2:
The reference pattern module segments the overlay measurement function into multiple reference patterns that can be independently controlled and positioned. By dividing the measurement function across multiple reference patterns within a single module that can be moved relative to the substrate, the system achieves precise overlay error measurement without requiring complex direct overlaps of multiple patterns on different layers
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 approach enables precise measurement of overlay errors between different layers, ensuring accurate alignment and reducing the need for multiple overlay measurement patterns, thus improving the efficiency and accuracy of lithography processes.
Implementation Method 1
determining overlay errors through diffracted light analysis
Data Source
AI summary
A method of overlay error measurement includes disposing a reference pattern module over a substrate. The substrate includes first and second overlay measurement patterns in first and second locations. The reference pattern module includes first and second reference patterns. The method includes creating a first overlap of the first reference pattern with the first overlay measurement pattern and a second overlap of the second reference pattern with the second overlay measurement pattern. The method further includes determining a first overlay error between the first reference pattern of the reference pattern module and the first overlay measurement pattern of the substrate and determining a second overlay error between the second reference pattern and the second overlay measurement pattern. The method also includes determining a total overlay error between the first and second overlay measurement patterns of the substrate based on the first and second overlay errors.