Double Patterning Layout Pattern Replacement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In semiconductor fabrication, double patterning techniques require multiple masks, leading to increased costs when design changes are needed, as existing methods often necessitate changes to all masks, even if only one mask needs updating, due to the complexity of maintaining minimum separator distances and avoiding odd loops in layout designs.
Innovation Solution
The method involves constructing 'keep-out' regions only around patterns formed on the same mask as the selected pattern to be replaced, allowing the replacement pattern to be rerouted without intersecting these regions or patterns on other masks, thus limiting changes to a single mask and maintaining minimum separator distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If double patterning decomposition is performed using two masks, then layout complexity is reduced and minimum line spacing is improved, but design change cost increases when photomasks need to be updated
Solution Approach 1:
The patent segments the design change process by identifying which specific patterns require updates and which do not. By analyzing the layout to determine patterns that can remain unchanged, the method allows selective updates to only necessary photomasks rather than requiring all masks to be regenerated, thus reducing design change costs while maintaining the precision benefits of double patterning
Solution Approach 2:
The patent performs preliminary analysis of the layout to identify patterns that do not require updates before photomask fabrication begins. This advance identification allows the system to prepare update plans that minimize the number of masks needing changes, reducing both time and cost associated with design modifications while preserving the manufacturing precision advantages
2Reliability
If photomasks are updated to correct design errors, then design reliability is improved, but manufacturing cost doubles when both masks must be changed
Solution Approach 1:
The patent applies local quality analysis by examining specific regions of the layout to determine which patterns are affected by design errors and which are not. This localized assessment allows updates to be confined to only those photomasks containing erroneous patterns, rather than requiring universal mask updates, thereby reducing the quantity of masks needing regeneration while ensuring design reliability is maintained in critical areas
Solution Approach 2:
The patent identifies patterns that can be recovered (kept unchanged) from the original photomask designs when only localized corrections are needed. By discarding only the specific erroneous patterns and recovering the valid portions of the layout, the method reduces the number of masks requiring complete regeneration, thus lowering manufacturing costs while maintaining design reliability
3Manufacturing precision
If minimum separator distances are maintained between all patterns, then manufacturing precision is improved, but layout flexibility decreases when rerouting is required
Solution Approach 1:
The patent introduces dynamic adaptability by allowing the minimum separator distance constraints to be selectively applied based on which mask a pattern belongs to. When patterns are assigned to different masks, the system can relax certain separator distance requirements between them, providing flexibility for rerouting while maintaining precision requirements for patterns on the same mask, thus balancing manufacturing precision with layout adaptability
Data Source
AI summary
A received layout identifies a plurality of circuit components to be included in an integrated circuit (IC) layer for double patterning the layer using two photomasks, the layout including a plurality of first patterns to be included in the first photomask and at least one second pattern to be included in the second photomask. A selected one of the first patterns has first and second endpoints, to be replaced by a replacement pattern connecting the first endpoint to a third endpoint. At least one respective keep-out region is provided adjacent to each respective remaining first pattern except for the selected first pattern. Data are generated representing the replacement pattern, such that no part of the replacement pattern is formed in any of the keep-out regions. Data representing the remaining first patterns and the replacement pattern are output.