Automated Density Violation Waiver in IC Layout Design
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Solution Overview
Problem
Conventional planarization methods in integrated circuit manufacturing often result in uneven surfaces due to differences in material density, leading to manufacturing defects such as holes and loss of contact, and existing techniques for waiving density violations are inefficient or require manual intervention.
Innovation Solution
The implementation of waiver regions in the layout design, identified by waiver identification items and geometric elements, allows for automatic determination and reporting of density violations based on a density check window overlap with waiver geometric items and threshold information, enabling efficient waiver of density violations without increasing capacitance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional planarization methods are used, then manufacturing process is simple, but surface unevenness occurs leading to manufacturing defects
Solution Approach 1:
The invention performs preliminary identification and marking of waiver regions before the density check process. By pre-defining geometric items that represent regions where density violations should be waived, the system avoids the need for complex post-processing analysis and manual intervention, thereby improving surface planarity assessment while maintaining process simplicity
Solution Approach 2:
The invention introduces waiver region geometric items as intermediary elements that mediate between the layout design and the density check process. These geometric items serve as markers that automatically indicate where density violations should be tolerated, eliminating the need for manual waiver decisions and reducing process complexity while improving manufacturing precision
2Manufacturing precision
If fill polygons are added to increase density, then planarity improves, but capacitance increases causing timing issues
Solution Approach 1:
The invention applies local quality by allowing density violations to be waived only in specific localized regions defined by geometric items, rather than uniformly applying fill polygons across the entire layout. This enables planarity improvement to be achieved locally where truly needed, while avoiding unnecessary fill structures that would increase capacitance in other regions
Solution Approach 2:
By pre-identifying and marking waiver regions with geometric items before the density check, the system determines in advance where fill polygons should NOT be added. This preliminary action prevents excessive capacitance increase by avoiding fill structures in regions where density violations are acceptable, while still achieving planarity where required
3Measurement precision
If manual waiver process is used, then accuracy is high, but productivity decreases due to manual intervention
Solution Approach 1:
The invention implements self-service by enabling the density check process to automatically recognize and waive violations in regions marked by geometric items. The system serves itself by using the pre-defined geometric markers to automatically determine which density violations to waive, eliminating the need for manual review while maintaining high accuracy, thereby significantly improving verification throughput
Solution Approach 2:
The geometric items act as intermediaries that carry waiver information from the layout design to the density check process. This intermediary mechanism enables automatic recognition of waiver regions without manual intervention, maintaining the accuracy of manual waiver decisions while achieving the productivity of automated processing
Data Source
AI summary
Waiver regions may be identified by waiver identification items. The waiver identification items may be determined based on conducting a density check process. Additionally or alternatively, reference patterns for pattern matching, cell names or markers may serve as the waiver identification items. Waiver geometric items may be created for the waiver regions and added to the layout design. Based on an overlap of a density check window with the waiver geometric items and waiving threshold information, a density violation in that density check window is determined to be reported as a density violation or a waived density violation with some implementations of the invention. With some other implementations of the invention, pattern density of a density check window may not be checked if an overlap of the density check window with the waiver geometric items is above a waiving threshold value.