Scattering Bar Segmentation for Lithography OPC
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional photolithography techniques face challenges in fabricating semiconductor structures with small features due to issues like obscured edges, missized patterns, and distorted patterns, which are exacerbated by the limitations of scattering bars in optical proximity correction (OPC), leading to lower yield rates and suboptimal lithography performance.
Innovation Solution
The method involves optimizing the placement and connection of scattering bars adjacent to feature edges, adjusting their lengths and separations to comply with mask fabrication restrictions, and using advanced lithography processes to enhance the effectiveness of OPC, ensuring accurate depth of focus and pattern density, thereby improving the precision and resolution of photolithographic patterning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If scattering bars are placed nearby or between to-be-imaged features to improve pattern sharpness, then lithography precision and resolution are improved, but the lithography performance is lowered due to restrictions of disposing scattering bars
Solution Approach 1:
The scattering bar is divided into multiple segments (first scattering bar segment, second scattering bar segment, third scattering bar segment) that can be independently positioned and configured. This segmentation allows each segment to be optimally placed in different locations relative to the target pattern, improving both precision and adaptability without violating disposal restrictions.
Solution Approach 2:
Different scattering bar segments are placed at different locations with different configurations (some adjacent to first edges, others adjacent to second edges). This local differentiation allows the scattering bars to provide optimized correction at specific critical locations while maintaining overall lithography performance across the entire pattern.
2Length of moving object
If smaller critical dimensions are pursued to fabricate semiconductor structures with smaller features, then feature size is reduced, but obscured edges, missized patterns, rounded corners, distorted patterns, or unresolvable patterns are induced
Solution Approach 1:
Scattering bars are placed in advance near the target pattern features before the actual imaging process. These pre-positioned scattering bars modify the optical field distribution ahead of time, compensating for expected diffraction and interference effects that would otherwise cause obscured edges, rounded corners, or distorted patterns in small-featured structures.
Solution Approach 2:
The scattering bars are strategically positioned to create preliminary optical interference patterns that counteract the harmful diffraction effects. By placing scattering bars at specific locations, the method pre-compensates for edge obscuration and pattern distortion before the main imaging occurs, thereby maintaining pattern accuracy even at smaller critical dimensions.
Data Source
AI summary
Present disclosure provides a mask and a method for fabricating a semiconductor device, the mask includes a target pattern having consecutive edges, a first scattering bar and a second scattering bar extending along a primary direction and adjacent to consecutive edges of the target pattern, wherein the first scattering bar and the second scattering bar partially overlaps in the primary direction, and a connecting segment connecting between a first end of the first scattering bar and a first end of the second scattering bar, wherein the first scattering bar is not parallel to the connecting segment.