Photomask Deflection Measurement via Multi-Directional Interference
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Solution Overview
Problem
In semiconductor manufacturing, photomask deflection during lithographic processes leads to defocusing issues, necessitating precise deflection control to achieve finer patterns and higher integration densities.
Innovation Solution
A deflection measuring device that radiates parallel lights from multiple directions onto a pattern transfer plate, detecting interference fringes to accurately measure and correct photomask deflection, thereby enhancing resolution and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photomask deflection is not controlled, then manufacturing process is simpler, but pattern formation accuracy deteriorates
Solution Approach 1:
The patent applies preliminary action by measuring photomask deflection before the lithographic exposure process using laser light interference. The deflection measurement is performed in advance on the photomask while it is in the exposure apparatus, allowing the system to detect and compensate for deflection issues before they affect pattern formation accuracy, thus resolving the contradiction between maintaining simple processes and achieving high precision.
2Manufacturing precision
If deflection measurement is performed, then pattern formation accuracy is improved, but measurement time is increased
Solution Approach 1:
The patent implements continuous deflection measurement during the photomask exposure process. The laser light continuously irradiates the photomask, and the deflection is measured in real-time without interrupting the exposure workflow. This continuous measurement approach maintains high deflection measurement accuracy while minimizing time loss, as the measurement occurs concurrently with the exposure process rather than as a separate step.
3Measurement precision
If multiple light directions are used for measurement, then deflection measurement accuracy is improved, but device complexity increases
Solution Approach 1:
The patent uses a single laser light source that serves multiple functions: it provides the measurement light, creates interference patterns, and enables deflection detection from multiple effective directions simultaneously. The laser light is irradiated onto the photomask from above, and by analyzing the interference fringes formed by the reflected light, the system achieves multi-directional measurement capability without requiring multiple separate light sources, thus improving deflection measurement accuracy while keeping the device configuration relatively simple.
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 improves the accuracy of deflection measurement and correction, allowing for finer pattern formation and increased integration density in semiconductor devices by effectively addressing photomask deflection, thus enhancing the manufacturing process.
Implementation Method 1
detects interference fringes of the parallel lights reflected from the effective region
Data Source
AI summary
According to one embodiment, a deflection measuring device that irradiates an effective region of a pattern transfer plate on which a pattern is formed, with parallel lights from at least two directions, and detects interference fringes of the parallel lights reflected from the effective region.