Layout Correction Method for DRAM Optical Proximity
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Solution Overview
Problem
Inaccurate optical proximity correction during the layout expansion of Dynamic Random Access Memory (DRAM) arrays due to neglecting optical diameter in smaller-size layout areas leads to non-uniform Critical Dimension (CD) and photoresist profile fluctuations, affecting product yield.
Innovation Solution
A method involving providing an initial layout, expanding it based on optical diameter considerations, correcting the expanded layout through reconstruction and inversion photoetching technology to achieve a uniform critical dimension, and obtaining a target layout that ensures reliable Optical Proximity Correction (OPC).
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of time
If a smaller-size layout area is selected for correction to save time, then correction time is reduced, but optical proximity correction accuracy deteriorates due to neglecting optical diameter effects
Solution Approach 1:
The patent applies preliminary action by expanding the layout area before performing optical proximity correction. This pre-expansion ensures that the correction process includes sufficient margin to account for optical diameter effects, thereby maintaining correction accuracy while still improving efficiency compared to traditional full-area correction methods.
2Manufacturing precision
If layout area is expanded into a larger array area, then optical proximity correction accuracy is improved, but correction complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the layout correction process into distinct stages: first expanding the layout area to account for optical effects, then performing the correction process. This segmentation allows the system to handle the expanded area systematically, reducing the perceived complexity by breaking down the correction task into manageable steps.
3Speed
If smaller-size layout area is used for correction, then processing speed is improved, but critical dimension uniformity deteriorates
Solution Approach 1:
The patent applies preliminary action by performing layout expansion before correction. This pre-expansion ensures that the correction process operates on an enlarged area that accounts for optical diameter effects, thereby achieving both improved processing speed (compared to traditional full-area correction) and maintained critical dimension uniformity through proper optical effect consideration.
Data Source
AI summary
A layout correction method is provided. The layout correction method includes: providing an initial layout; expanding the initial layout to obtain an expanded layout; correcting the expanded layout to obtain a corrected layout; and obtaining a target layout based on the corrected layout.