Spatial Light Modulator Alignment for Precise Exposure Correction
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Solution Overview
Problem
Existing exposure apparatuses using spatial light modulators face challenges in accurately measuring and correcting positional deviations of reflecting surfaces due to manufacturing errors and thermal expansion, which affect the precision of pattern formation on substrates.
Innovation Solution
The exposure apparatus incorporates a detection unit with a larger field of view and a position changing mechanism to detect light from reflecting surfaces, allowing for precise measurement of positional relationships and correction of deviations using a calculation unit to adjust the spatial light modulator's position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a detection unit with a larger field of view is used, then the measurement coverage of the spatial light modulator is improved, but the measurement precision for individual reflecting surfaces deteriorates
Solution Approach 1:
The detection unit is divided into multiple detection optical systems, each responsible for detecting light from specific regions of the spatial light modulator. This segmentation allows each subsystem to maintain high measurement precision for its designated area while collectively covering the entire surface area through coordinated operation of multiple systems.
2Area of stationary object
If multiple detection optical systems are used to cover the entire spatial light modulator, then the measurement coverage is improved, but the device complexity increases
Solution Approach 1:
Multiple detection optical systems are merged into a single integrated detection unit that operates as a coordinated system. The individual systems share common components such as the light source and processing unit, and their detection results are combined to provide comprehensive coverage of the spatial light modulator surface, thereby reducing overall system complexity compared to using separate independent systems.
3Area of stationary object
If the spatial light modulator is repositioned to face different detection units, then the measurement coverage is improved, but the operation time increases
Solution Approach 1:
The detection unit is designed with dynamic repositioning capability, allowing it to switch between different detection optical systems without requiring physical movement of the spatial light modulator. This dynamic switching enables the system to measure different regions of the spatial light modulator rapidly by activating the appropriate detection optical system for each region, significantly reducing measurement time compared to mechanical repositioning.
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 solution enables accurate measurement and correction of positional deviations, enhancing the precision of pattern formation on substrates and improving the overall performance of the exposure apparatus.
Implementation Method 1
a first detection unit (6) including a first detection optical system (30) and detecting light from the reflecting surface
Data Source
Figure 1
Figure 2(a)~2(b)
Figure 3
AI summary
An exposure apparatus includes: an exposure illumination optical system illuminating a spatial light modulator which has a plurality of spatial light modulation elements having a reflecting surface disposed on a disposition plane; a projection optical system projecting light from the spatial light modulator to an exposed substrate; a first detection unit detecting light from the reflecting surface; a second detection unit which is a detection unit detecting light from the reflecting surface and has a detection field of view larger than that of the first detection unit; and a position changing mechanism changing a positional relationship among the first detection unit, the second detection unit, and the spatial light modulator to either a first positional relationship in which the spatial light modulator faces the first detection unit and a second positional relationship in which the spatial light modulator faces the second detection unit.