Layer-Specific Lithography Corrections for Overlay Accuracy
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithographic processes face challenges in accurately aligning and correcting distortions across multiple layers of semiconductor devices, particularly when different classes of lithographic apparatuses with varying capabilities are used, leading to inefficiencies in overlay accuracy and throughput.
Innovation Solution
A method and interface for determining actuatable corrections in a lithographic process that considers the origin of errors from specific layers, allowing direct input of requested corrections into the lithographic apparatus, and optimizing corrections based on the capabilities of the apparatus used for each layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If different classes of lithographic apparatuses with varying capabilities are used for different layers, then versatility and adaptability improve, but device complexity and coordination difficulty increase
Solution Approach 1:
The patent segments the lithographic process into layer-specific processing steps, where different classes of lithographic apparatuses are assigned to different layers based on their capabilities. Each apparatus class has optimized parameters and correction capabilities tailored to its specific layer processing requirements, allowing the system to handle diverse layer characteristics without requiring a single complex apparatus to manage all scenarios.
Solution Approach 2:
The system dynamically selects and configures appropriate lithographic apparatuses for each layer based on real-time process requirements, error characteristics, and apparatus capabilities. This dynamic allocation allows the manufacturing process to adapt to varying layer complexities while optimizing resource utilization and maintaining overall process efficiency.
2Manufacturing precision
If extensive measurement and correction operations are performed to achieve accurate overlay, then manufacturing precision improves, but productivity and throughput decrease
Solution Approach 1:
The patent implements preliminary measurement and correction operations for each layer before proceeding to the next layer. By performing alignment measurements, distortion mapping, and correction calculations in advance during the exposure process, the system ensures high overlay accuracy without requiring extensive post-processing measurements that would bottleneck throughput.
Solution Approach 2:
The system maintains continuous measurement and correction operations throughout the multi-layer lithographic process. Rather than performing batch measurements between layers, the apparatus continuously acquires alignment data, updates distortion models, and applies corrections in real-time during each exposure step, eliminating idle time and maintaining high productivity while ensuring precision.
3Manufacturing precision
If sophisticated fine-tuning steps and resolution enhancement techniques are applied to achieve low k1 lithography, then manufacturing precision improves, but process complexity and time increase
Solution Approach 1:
The patent applies resolution enhancement techniques and fine-tuning steps selectively based on the specific requirements of each layer and feature type. Rather than uniformly applying all sophisticated techniques to every layer, the system identifies critical layers and features that require enhanced precision and concentrates computational resources and process steps on those specific areas, reducing overall process complexity while maintaining necessary precision.
Solution Approach 2:
The system dynamically adjusts lithographic parameters such as numerical aperture, illumination conditions, and focus settings for each layer based on the required feature dimensions and pattern complexity. By optimizing parameters specifically for low k1 requirements where needed, the system achieves high manufacturing precision without permanently committing to the most complex configuration across all processing steps.
4Manufacturing precision
If tight control loops are used to control stability of the lithographic apparatus, then manufacturing precision improves, but response time and adaptability to substrate variations may be reduced
Solution Approach 1:
The patent implements feedback control loops that continuously monitor lithographic process parameters and substrate characteristics, comparing actual measurements against target specifications. The system uses this feedback to dynamically adjust exposure parameters, alignment corrections, and focus settings for each layer, maintaining high manufacturing precision while adapting to substrate variations through real-time parameter optimization rather than rigid fixed-parameter control.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Disclosed is method of determining an actuatable correction for a lithographic process. The method comprises obtaining a modeled error and/or a requested correction, said modeled error relating to an error of said lithographic process and said requested correction comprising a requested correction for said modeled error; and determining said actuatable correction in dependence on from which layer the modeled error originates.