Segmented Alignment Mark with Shielding Region for Photolithography
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In photolithography exposure processes, alignment errors occur due to disturbance objects on the exposure machine stage interfering with the identification of alignment marks, leading to reduced accuracy and production efficiency.
Innovation Solution
An alignment mark comprising an opaque alignment region, a transparent peripheral region, and a non-overlapping opaque shielding region is used, allowing for accurate position information acquisition by creating a significant gray scale difference and shielding disturbance objects, thereby improving alignment accuracy and reducing errors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional alignment marks without shielding regions are used, then the structure is simple, but disturbance objects on the exposure machine stage interfere with alignment mark identification, reducing alignment accuracy
Solution Approach 1:
The alignment mark is segmented into three distinct regions: an alignment region for identification, a peripheral region for contrast enhancement, and a shielding region for blocking disturbance objects. This segmentation allows each region to perform its specific function independently, resolving the contradiction between improving alignment accuracy and maintaining structural simplicity.
Solution Approach 2:
Different regions of the alignment mark are assigned different optical properties: the alignment region and shielding region are opaque, while the peripheral region is transparent. This local differentiation of properties enables the mark to simultaneously achieve accurate identification, contrast enhancement, and disturbance blocking without requiring complete structural complexity throughout.
2Measurement precision
If the peripheral region is made transparent to enhance contrast, then alignment region identification is improved, but disturbance objects remain visible and cause interference
Solution Approach 1:
The harmful effect of disturbance objects is extracted and isolated by introducing a dedicated shielding region that specifically targets and blocks these disturbances. This allows the peripheral region to remain transparent for contrast enhancement while the shielding region independently handles the interference problem, resolving the contradiction between identification improvement and disturbance blocking.
Solution Approach 2:
The shielding region acts as an intermediary element between the alignment region and the disturbance objects. It selectively blocks harmful light from disturbance objects while allowing the alignment region's signal to pass through, thereby mediating between the need for clear identification and the need to eliminate interference.
3Manufacturing precision
If multiple regions are added to the alignment mark to block disturbances, then alignment accuracy is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The alignment mark structure is merged with the existing black matrix layer in the display substrate manufacturing process. By combining the alignment mark formation with the black matrix patterning step, the patent achieves improved alignment accuracy without adding separate manufacturing steps, thereby resolving the contradiction between manufacturing precision and ease of manufacture.
4Object-affected harmful factors
If the alignment mark uses opaque materials for both alignment and shielding regions, then disturbance blocking is effective, but contrast with the transparent peripheral region is reduced
Solution Approach 1:
The alignment mark employs asymmetric optical properties across its regions: the peripheral region is transparent while the alignment and shielding regions are opaque. This asymmetry creates a significant gray scale difference that enhances contrast for identification, while the strategic placement of opaque regions ensures effective disturbance blocking, resolving the contradiction between contrast and blocking effectiveness.
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 mark enhances the accuracy of substrate-mask alignment, reduces alignment errors, and improves production efficiency by clearly distinguishing the alignment region and shielding disturbance objects during exposure alignment processes.
Implementation Method 1
The peripheral region is transparent, and the alignment region and the shielding region are opaque
Implementation Method 2
The shielding region is disposed around at least a part of the outer contour of the alignment region, and is non-overlapped with the peripheral region
Data Source
AI summary
An alignment mark includes an alignment region, a peripheral region and a shielding region. The alignment region has an outer contour; the peripheral region is disposed around at least a part of the outer contour of the alignment region; the shielding region is disposed around at least a part of the outer contour of the alignment region and is non-overlapped with the peripheral region; and the alignment region and the shielding region are opaque, and the peripheral region is at least partially transparent.