Overlay Control System Multi-Layer Alignment Correction
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Solution Overview
Problem
Current overlay control systems in semiconductor manufacturing cannot simultaneously achieve accurate alignment of mask patterns with respect to multiple underlying layers, as they are typically designed to address overlay accuracy in one direction independently, failing to satisfy accuracy requirements in orthogonal directions for different layers.
Innovation Solution
A system and method that combines processing and inspection data to create a correction data table, allowing for the calculation of a corrected control set value for exposure tools, which includes a processing data receiving module, inspection data receiving module, data combining module, and control set value calculation module to ensure accurate overlay alignment across multiple layers by averaging or weighting inspection values.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If typical overlay control is used to improve overlay accuracy with respect to one underlying layer, then overlay accuracy for that specific layer is improved, but overlay accuracy with respect to other underlying layers cannot be satisfied simultaneously
Solution Approach 1:
The patent combines multiple inspection data strings from different underlying layers into a single correction data table. The data combining module integrates inspection values from multiple layers, and the control set value calculation module computes a unified corrected control set value that simultaneously addresses overlay accuracy for all underlying layers, not just one layer at a time.
Solution Approach 2:
The overlay control system is designed to handle multiple underlying layers universally. The system can process inspection data from any number of underlying layers and calculate a corrected control set value that applies to the exposure process for the target layer, making the control mechanism versatile across different layer configurations and inspection scenarios.
2Manufacturing precision
If overlay accuracy is defined independently for each direction (X and Y directions) with respect to different underlying layers, then direction-specific accuracy requirements can be met, but typical overlay control cannot be utilized
Solution Approach 1:
The patent segments the overlay control into directional components by processing inspection data separately for X and Y directions. The system can define different overlay accuracy requirements for each direction and calculate corrected control set values that address each direction's specific needs while maintaining a unified control framework.
Solution Approach 2:
The patent extends the overlay control from single-layer to multi-dimensional multi-layer control. By incorporating inspection data from multiple underlying layers and processing them in a unified correction data table, the system adds the dimension of multiple layers while maintaining directional (X and Y) control capabilities, effectively moving from 2D to 3D overlay control space.
Data Source
AI summary
A system for controlling an overlay includes a processing data receiving module receiving a processing data string describing a name of an exposure process for a target layer and an original control set value of overlays between the target layer and underlying layers below the target layer; an inspection data receiving module receiving inspection data strings describing names of inspection processes and inspection values determined by the inspection processes inspecting respective overlays between the target layer and the underlying layers; a data combining module combining the processing data string and each of the inspection data strings using a combining condition table so as to create a correction data table; and a control set value calculation module calculating a corrected control set value based on the inspection values of the correction data table.