Bonding Exposure Alignment Limits for Wafer Magnification Drift
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing exposure apparatuses struggle to accurately correct wafer magnification components during the bonding process of semiconductor circuit substrates, leading to overlay deviations that affect yield and precision in semiconductor device manufacturing.
Innovation Solution
An exposure apparatus that calculates and adjusts alignment correction values for wafer magnification components using a target value, upper and lower limits, and function approximation to ensure the magnification component is within specified ranges, thereby improving overlay accuracy and reducing variations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional exposure apparatuses are used for bonding process exposure, then the exposure process can be completed, but overlay precision deteriorates due to uncorrected wafer magnification components
Solution Approach 1:
The system performs preliminary measurement of wafer magnification components before the bonding exposure process. Alignment marks are measured and wafer magnification components are calculated in advance, allowing correction values to be determined before the actual exposure, thereby preventing overlay precision deterioration.
Solution Approach 2:
The system implements a feedback mechanism where alignment mark measurement results are used to calculate wafer magnification components, which then generate alignment correction values. These correction values are fed back to adjust the exposure process, creating a closed-loop control system that continuously improves overlay precision.
2Manufacturing precision
If alignment correction values are not adjusted within specified ranges, then the exposure process is simple, but overlay precision and yield deteriorate
Solution Approach 1:
The system dynamically adjusts alignment correction values based on measured wafer magnification components. Instead of using fixed correction values, the system calculates and applies variable correction values that adapt to each wafer's specific magnification characteristics, thereby improving overlay precision without requiring overly complex manual intervention.
Solution Approach 2:
The system changes the parameters of alignment correction values based on measured data. By calculating wafer magnification components from alignment mark measurements and using these to determine appropriate correction values within specified ranges, the system optimizes overlay precision through parameter adjustment rather than structural complexity.
3Manufacturing precision
If wafer magnification components are not corrected, then the exposure process is fast, but bonding overlay accuracy deteriorates
Solution Approach 1:
The system performs wafer magnification measurement and correction value calculation as preliminary actions before the bonding exposure. By measuring alignment marks and calculating correction values in advance, the system prepares all necessary correction data beforehand, allowing the actual exposure process to proceed efficiently without time-consuming adjustments during exposure.
Solution Approach 2:
The system replaces manual mechanical adjustment methods with automated optical measurement and computational correction. By using optical alignment mark measurement and computational algorithms to calculate correction values, the system achieves faster and more accurate magnification correction compared to traditional mechanical adjustment methods.
4Reliability
If alignment correction values exceed specified limits, then the correction covers large variations, but random components increase and yield deteriorates
Solution Approach 1:
The system uses feedback control to monitor and adjust alignment correction values within specified management limits. By continuously measuring alignment marks, calculating wafer magnification components, and adjusting correction values to remain within predetermined ranges, the system maintains both alignment precision and yield without excessive correction that would increase random components.
Solution Approach 2:
The system carefully manages the parameters of alignment correction values to remain within optimal ranges. By calculating correction values based on measured wafer magnification components and constraining them within specified limits, the system achieves the right balance between correcting alignment errors and avoiding excessive correction that would degrade yield.
Data Source
AI summary
An exposure apparatus according to one embodiment includes a stage and a control device. In an exposure process, the control device is configured to: calculate a calculated value of a magnification component by performing function approximation on measurement results of three or more alignment marks arranged on the substrate; set a first lower limit value and/or a first upper limit value for an alignment correction value of a magnification component; in a case where the first lower limit value is set and the calculated value is less than the first lower limit value, set the alignment correction value of the magnification component to a second correction value that is larger than the calculated value and smaller than the first correction value.