Mask Pattern Hotspot Correction via Segmented OPC
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The increasing complexity and computational challenges in determining write patterns and mask patterns for lithography processes, particularly due to the difficulty in correcting distortions and artifacts caused by the wave nature of light, lead to inefficiencies and high costs in manufacturing integrated circuits and semiconductor wafers.
Innovation Solution
A computer system method that identifies and corrects regions violating predetermined rules in mask patterns by generating a new mask pattern using a different technique, applying Optical Proximity Correction, and merging it with the original pattern to ensure compliance with manufacturing rules, thereby improving the accuracy and efficiency of lithographic processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If existing techniques (OPC, RET) are used to pre-distort mask patterns to improve resolution, then manufacturing precision is improved, but device complexity and computation time increase significantly
Solution Approach 1:
The patent segments the mask pattern into multiple layers (e.g., main pattern layer and assist feature layer) and processes them separately. This segmentation reduces the computational complexity of each individual layer while maintaining overall manufacturing precision, as each layer can be optimized independently rather than processing the entire complex pattern at once.
Solution Approach 2:
The patent applies preliminary actions by pre-defining rule sets and correction parameters before actual mask pattern generation. By establishing correction rules, hotspot detection criteria, and assist feature parameters in advance, the system reduces real-time computational complexity while ensuring manufacturing precision through pre-planned corrections.
2Productivity
If feature density on integrated circuit dies is increased to meet demand, then productivity is improved, but manufacturing precision deteriorates due to increased complexity of determining write patterns and mask patterns
Solution Approach 1:
The patent applies local quality by detecting hotspots (local regions with manufacturing defects) and applying corrections specifically to those areas rather than uniformly across the entire mask pattern. Assist features are strategically placed only where needed to correct local optical proximity effects, maintaining high manufacturing precision even as overall feature density increases.
Solution Approach 2:
The patent introduces assist features as intermediary elements that mediate between the main pattern features and the optical system. These intermediary features help control light diffraction and interference patterns, enabling higher feature density while maintaining manufacturing precision by acting as optical mediators in the lithography process.
3Adaptability or versatility
If multiple potential solutions exist in the solution space for pre-distorted mask patterns, then adaptability is improved, but loss of time increases due to time-consuming identification of suitable patterns
Solution Approach 1:
The patent implements feedback mechanisms by evaluating multiple candidate mask patterns against predefined criteria and selecting the optimal solution based on hotspot reduction and manufacturing feasibility. The system provides feedback on pattern quality metrics and uses this information to iteratively improve the selected pattern, reducing the time needed to identify suitable patterns while maintaining adaptability.
Solution Approach 2:
The patent applies parameter changes by systematically varying key parameters (such as assist feature size, spacing, and placement) across multiple candidate solutions and evaluating their impact on hotspot formation. By changing parameters in a structured manner and using predefined selection criteria, the system efficiently navigates the solution space to identify optimal patterns without excessive time consumption.
Data Source
AI summary
Embodiments of a method for determining a mask pattern to be used on a photo-mask in a lithography process are described. This method may be performed by a computer system. During operation, this computer system receives at least a portion of a first mask pattern including first regions that violate pre-determined rules associated with the photo-mask. Next, the computer system determines a second mask pattern based on at least the portion of the first mask pattern, where the second mask pattern includes second regions that are estimated to comply with the pre-determined rules. Note that the second regions correspond to the first regions, and the second mask pattern is determined using a different technique than that used to determine the first mask pattern.