Alignment Mark Auxiliary Pattern for Scatter-Light Noise Suppression
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Solution Overview
Problem
In semiconductor manufacturing, the imprint method for forming fine patterns on wafers faces challenges in achieving high alignment accuracy due to noise generated by scattered light at the ends of alignment marks during the alignment process.
Innovation Solution
The use of auxiliary patterns opposite to the main alignment patterns at the ends of the alignment marks on both the template and the wafer, which are designed to suppress noise by reflecting and transmitting inspection light in a specific configuration, thereby improving alignment accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If alignment marks are used for alignment process, then alignment function is achieved, but noise due to scattered light is generated at the end of the alignment mark
Solution Approach 1:
The alignment mark is segmented into a main pattern portion and an auxiliary pattern portion. The auxiliary pattern is positioned at the end of the main pattern and is configured to suppress scattered light generation. This segmentation allows the alignment mark to fulfill its alignment function while reducing the harmful scattered light noise at its ends.
Solution Approach 2:
The auxiliary pattern converts the harmful scattered light effect into a beneficial one by designing it to have light-reflecting and light-transmitting properties that suppress the scattered light noise. The auxiliary pattern's specific configuration transforms what would be a source of noise into a noise-suppressing element, improving overall alignment accuracy.
2Measurement precision
If auxiliary patterns are added to suppress noise, then alignment accuracy is improved, but device complexity increases
Solution Approach 1:
The auxiliary pattern is applied locally only at the end of the main pattern portion of the alignment mark, rather than throughout the entire alignment mark. This localized application suppresses scattered light noise at the critical end region while minimizing the increase in overall device complexity. The auxiliary pattern's specific configuration provides noise suppression with minimal additional structural 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
This configuration effectively reduces noise near the ends of the alignment marks, allowing for precise detection of position shifts and accurate alignment between the template and the wafer, enhancing the overall alignment process.
Implementation Method 1
The first auxiliary pattern is configured as a pattern opposite to the repeating pattern in a region outside an end of the first main pattern... suppress noise by reflecting and transmitting inspection light
Data Source
AI summary
A template of one embodiment includes an alignment mark. The alignment mark includes a first main pattern and a first auxiliary pattern. In the first main pattern, a first part and a second part are disposed according to a predetermined repeating pattern. The first auxiliary pattern is configured as a pattern opposite to the repeating pattern in a region outside an end of the first main pattern.