Chemo-epitaxy DSA Defect Reduction via Dummy Pattern Insertion
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Solution Overview
Problem
Conventional techniques for chemo-epitaxy Directed Self-Assembly (DSA) fail to optimally design internal and external dummy guiding patterns, leading to defects near the edge of circuit blocks and across large gaps in Fin Field Effect Transistor (FinFET) integrated circuits, due to non-uniform pattern spacing and dimensions.
Innovation Solution
A method is introduced to detect vertical spacings between guiding patterns and insert internal and external dummy patterns, along with anti-taper structures, to maintain uniformity and reduce defects, by determining specific predetermined distances for dummy placement and structure insertion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional techniques are used for chemo-epitaxy DSA process, then the process can be implemented with standard procedures, but DSA defects form near the edge of circuit patterns due to non-uniform pattern spacing
Solution Approach 1:
The patent applies preliminary action by inserting dummy guiding patterns into the layout before the actual chemo-epitaxy DSA process. These dummy patterns are strategically placed in large empty areas and at boundaries to pre-establish uniform spacing, ensuring that the self-assembly process has consistent guidance throughout the substrate, thereby preventing edge-related defects.
Solution Approach 2:
The patent implements local quality by applying different dummy pattern configurations to different regions of the substrate. Internal dummy patterns are placed within large empty areas, while external dummy patterns are positioned at boundaries, and boundary dummy patterns are inserted at specific locations. This region-specific approach ensures that each area receives the appropriate guidance structure needed for uniform pattern spacing.
2Manufacturing precision
If dummy patterns are inserted to maintain uniform spacing, then pattern spacing uniformity is improved, but the complexity of the layout design increases
Solution Approach 1:
The patent applies segmentation by dividing the dummy pattern insertion into distinct categories: internal dummy patterns for large empty areas, external dummy patterns for boundaries, and boundary dummy patterns for specific locations. This segmentation allows the complex task of ensuring uniform spacing across the entire substrate to be broken down into manageable, rule-based subtasks that can be systematically applied.
Solution Approach 2:
The patent utilizes parameter changes by adjusting the dimensions, spacing, and positioning of dummy patterns based on local requirements. The system modifies geometric parameters of the dummy patterns to match the specific needs of different regions, such as adjusting the size of internal dummies based on the area of empty space or positioning external dummies at specific boundary locations, thereby maintaining uniformity without requiring a completely complex design.
3Reliability
If external dummy patterns are added to reduce boundary defects, then DSA defect reduction is improved, but the manufacturing process steps increase
Solution Approach 1:
The patent applies merging by combining the identification and insertion of multiple types of dummy patterns (internal, external, and boundary) into a unified automated layout modification process. The system integrates these different dummy pattern operations into a single workflow that can be executed as part of the standard design process, thereby reducing the perceived increase in manufacturing steps while maintaining the reliability benefits.
Data Source
AI summary
A method, system, and non-transitory computer readable medium for reducing chemo-epitaxy directed-self assembly (DSA) defects of a layout of a guiding pattern include inserting an internal dummy between a first portion of the guiding pattern and a second portion of the guiding pattern if a vertical spacing is equal to or greater than a first predetermined distance, inserting a first external dummy along an external edge of the guiding pattern in a vertical direction if the vertical spacing is greater than a second predetermined distance, and inserting an anti-taper structure on the first external dummy if a second distance from the external edge of the guiding pattern to an edge of the first external dummy is greater than a first distance.