IC Routing Algorithm for Double Patterning Color Conflict Prevention
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lithography technologies face limitations in printing smaller feature sizes due to wavelength and numerical aperture constraints, leading to challenges in manufacturing integrated circuits with shrinking dimensions, and double patterning methods struggle with odd cycles and color conflicts, which can result in manufacturing issues and increased costs.
Innovation Solution
A method and system for electronic design automation that ensures successful manufacturing with double patterning by constraining the routing configuration to prevent color conflicts and odd cycles, using a routing algorithm that assigns preferred directions to wires and allows wrong-way connections with penalties, ensuring that the layout can be successfully manufactured without color conflicts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional lithography is used to print smaller features, then manufacturing capability is improved, but manufacturing precision deteriorates due to wavelength and numerical aperture constraints
Solution Approach 1:
The patent applies segmentation by dividing the patterning process into multiple discrete steps (first lithography step, first etch step, second lithography step, second etch step) rather than attempting to print all features in a single step. This multi-step segmentation allows each step to work within achievable lithographic limits while the cumulative effect achieves the desired fine feature dimensions that would be impossible in a single step.
Solution Approach 2:
The patent employs preliminary action by performing the first lithography and etch steps to create initial patterned features and mandrels before performing the second lithography and etch steps. These preliminary structures serve as templates and guides for the subsequent patterning steps, enabling precise feature formation that would be unachievable through direct single-step lithography.
2Manufacturing precision
If double patterning is used to achieve smaller features, then manufacturing precision is improved, but device complexity increases due to multiple lithography and etch steps
Solution Approach 1:
The patent applies self-service through self-aligned double patterning where the structures created in the first lithography and etch steps automatically serve as alignment references and templates for the second set of steps. The mandrels and patterned features formed preliminarily guide the subsequent patterning without requiring additional complex alignment systems or external referencing, thereby reducing process complexity despite multiple steps.
Solution Approach 2:
The patent merges the patterning and etching operations into integrated sequences where lithography and etching steps are combined to achieve both pattern transfer and feature formation simultaneously. This merging reduces the number of separate, independent process modules required compared to traditional multi-step approaches, simplifying the overall device complexity.
3Reliability
If routing is constrained to prevent color conflicts, then manufacturing reliability is improved, but routing flexibility deteriorates
Solution Approach 1:
The patent applies parameter changes by systematically varying the color assignments and routing parameters within the double patterning framework. By changing these parameters according to the color conflict prevention rules, the routing algorithm can adapt to different design requirements while maintaining manufacturing reliability. The parameters are modified within constrained ranges that ensure no color conflicts occur.
Solution Approach 2:
The patent employs dynamics by implementing a routing algorithm that dynamically adjusts routing paths and color assignments based on real-time detection of potential color conflicts. Rather than using fixed, rigid routing rules, the system dynamically modifies routing decisions to prevent conflicts while maintaining flexibility. This dynamic adaptation allows the routing to respond to different layout configurations without sacrificing manufacturing reliability.
Data Source
AI summary
Disclosed are a method, apparatus, and program product for routing an electronic design using double patterning that is correct by construction. The layout that has been routed will by construction be designed to allow successful manufacturing with double patterning, since the router will not allow a routing configuration in the layout that cannot be successfully manufactured with double patterning.