Substrate Alignment Mark Layout for Precise Diffraction Positioning
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Solution Overview
Problem
Existing substrate alignment processes during semiconductor manufacturing suffer from errors and reduced optical performance, which affect the accuracy of the exposure process.
Innovation Solution
The substrate structure incorporates alignment marks with specific patterns, such as first and second main patterns forming a quadrangle shape, and separation grooves to enhance optical performance and reduce process-related influences, improving alignment precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional alignment marks are used, then the alignment process can be performed, but error occurrence increases and optical performance deteriorates
Solution Approach 1:
The alignment mark is divided into multiple segments including first and second main patterns, first and second sub-patterns, and separation grooves. This segmentation allows each component to contribute specifically to optical performance, with main patterns providing primary alignment signals and sub-patterns enhancing diffraction characteristics, thereby improving measurement precision while maintaining reliability
Solution Approach 2:
The alignment mark employs asymmetric pattern designs where the first main pattern extends in a first direction and the second main pattern extends in a second direction perpendicular to the first. This asymmetric configuration optimizes diffraction beam generation in different directions, improving alignment accuracy without increasing error occurrence
2Ease of manufacture
If simple alignment mark patterns are used, then manufacturing is easier, but optical performance is reduced
Solution Approach 1:
The alignment mark incorporates patterns extending in multiple directions (first direction and second direction perpendicular thereto), transforming a simple one-dimensional pattern into a two-dimensional quadrangle configuration. This dimensional enhancement improves optical performance by generating more robust diffraction signals while maintaining manufacturability through standard photolithography processes
3Measurement precision
If alignment marks with increased pattern complexity are used, then optical performance improves, but device complexity increases
Solution Approach 1:
The alignment mark structure nests sub-patterns within the broader main patterns, with first and second sub-patterns positioned within the regions defined by the first and second main patterns. This nested configuration allows the simpler main patterns to provide overall structure while the nested sub-patterns enhance optical performance, achieving high alignment precision without excessive device complexity
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 proposed alignment marks reduce error occurrence and enhance optical performance, leading to improved alignment accuracy and stability in semiconductor manufacturing processes.
Implementation Method 1
a technique for calculating the position of the alignment mark through intensity and relative phase difference generated by overlapping diffraction beams diffracted from the alignment mark
Data Source
AI summary
A substrate structure including a substrate, and an alignment mark on the substrate and configured to align an alignment of the substrate may be provided. The alignment mark may include a first main pattern in which a first main segment extending in a first direction repeats in a second direction perpendicular to the first direction, and a second main pattern in which a second main segment extending in the second direction repeats in the first direction. When viewed in a plan view, the first main pattern and the second main pattern ma define a quadrangle pattern, and the first main pattern and the second main pattern may be configured to diffract a light incident on the alignment mark.