Lithography Hotspot Correction via Database Pattern Matching
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Solution Overview
Problem
Current methods for detecting and correcting lithography hotspots in IC chip layouts are inefficient, leading to false alarms and labor-intensive manual corrections, especially at nanometer scales, due to the complexity of design layouts and computational burdens in the RET/OPC stage.
Innovation Solution
An automated system that performs lithography compliance checking, uses a hotspot database for pattern matching and correction guidance, and applies local rip-up and reroute operations to identify and correct lithography hotspots, maintaining signal connectivity and preventing DRC violations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If rule-based detection is used to identify lithography hotspots, then detection coverage is improved, but false alarm rate increases
Solution Approach 1:
The detection process is segmented into two distinct phases: rule-based detection to identify potential hotspots, and database-based pattern matching to verify and filter true hotspots. This segmentation allows the system to maintain high detection coverage while reducing false alarms by cross-referencing against a curated database of known problematic patterns.
Solution Approach 2:
A hotspot database serves as an intermediary between rule-based detection and final hotspot identification. The database contains pre-characterized patterns of actual lithography hotspots and acts as a filter to validate detections from rule-based methods, thereby reducing false alarms while maintaining detection accuracy.
2Measurement precision
If manual correction is used to fix lithography hotspots, then correction accuracy can be improved, but productivity decreases
Solution Approach 1:
The system performs self-service by automatically generating correction actions based on database patterns. When a lithography hotspot is detected and matched in the database, the system automatically applies the pre-determined correction without requiring manual designer intervention, thereby maintaining high correction speed while ensuring accuracy through database-guided corrections.
Solution Approach 2:
Correction strategies are prepared in advance and stored in the hotspot database during database construction. When hotspots are detected, these pre-prepared correction actions are directly applied, eliminating the need for time-consuming manual analysis and correction while maintaining high accuracy through proven correction patterns.
3Reliability
If RET/OPC stage is used to correct lithography hotspots, then correction capability is improved, but computational burden increases
Solution Approach 1:
The hotspot database is constructed in advance containing patterns and correction strategies for known lithography hotspots. This preliminary preparation allows the system to quickly match and correct hotspots during layout verification without requiring computationally intensive RET/OPC processing, thereby reducing computational burden while maintaining correction capability.
Solution Approach 2:
The correction process is segmented into database-based pattern matching for straightforward cases and RET/OPC processing only for complex or novel hotspots. This segmentation allows the majority of corrections to be handled efficiently through pattern matching, reserving computationally intensive RET/OPC processing only when necessary, thereby reducing overall computational burden.
4Manufacturing precision
If design rules are increased for sub-65 nm IC designs, then manufacturing precision can be improved, but device complexity increases
Solution Approach 1:
Instead of manually managing complex design rules, the system creates a curated copy of actual lithography hotspot patterns from manufacturing data and stores them in a database. This copying approach simplifies the representation of manufacturing requirements from complex rule sets into concrete pattern examples, making the system easier to manage while maintaining manufacturing precision.
Solution Approach 2:
The system automatically adapts to new design rules and hotspot patterns by learning from manufacturing data and updating the hotspot database. This self-service capability eliminates the need for manual rule updates and reduces the complexity of managing design rule changes, as the system autonomously incorporates new requirements through pattern extraction and database updates.
Data Source
AI summary
One embodiment of the present invention provides a system that verifies an integrated circuit (IC) chip layout. During operation, the system receives a layout of an IC chip after the layout has gone through a place-and-route operation. Next, the system performs a lithography compliance checking (LCC) operation on the layout to detect lithography hotspots within the layout, wherein each lithography hotspot is associated with a local routing pattern around the lithography hotspot. Next, for each detected lithography hotspot, the system compares the associated local routing pattern against a hotspot database to determine if the local routing pattern matches an entry in the hotspot database, which stores a set of known hotspot configurations. If so, the system corrects the lithography hotspot using correction guidance information associated with the hotspot configuration stored in the hotspot database. Otherwise, the system corrects the lithography hotspot by performing a local rip-up and reroute on the local routing pattern, iteratively, until achieving convergence or given number of iterations.