Metal Line and Via Layout Correction for Lithography Window Expansion
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Solution Overview
Problem
The reduction of critical dimensions and increased circuit density in semiconductor manufacturing leads to excessively small lithography process windows for metal lines and vias, causing defects such as bridge defects, necking, and open circuits, which affect product yield.
Innovation Solution
An optical proximity correction method that enlarges connection vias along the width direction and translates influencing metal line segments to expand the lithography process window, without reducing the dimensions of interconnection metal lines, thereby reducing bridge defects and avoiding necking and open circuits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the critical dimensions are reduced and circuit density is increased, then the circuit density is improved, but the lithography process window becomes excessively small
Solution Approach 1:
The patent applies preliminary action by performing hole expansion processing on connection vias and translation processing on influencing metal line segments before the actual lithography process. This preprocessing modifies the layout to anticipate and compensate for optical proximity effects, thereby expanding the lithography process window while maintaining high circuit density. The dimension expansion amount is determined based on the current lithography process window to achieve optimal compensation.
2Quantity of substance
If the spacing between metal lines and dimension of vias is reduced, then the circuit density is improved, but bridge defects occur
Solution Approach 1:
The patent applies preliminary anti-action by translating influencing metal line segments away from interconnection metal lines by a distance equal to the dimension expansion amount of connection vias. This creates a buffer zone that prevents bridge defects between adjacent metal lines during lithography. The translation distance is precisely calculated based on the via expansion amount to ensure adequate spacing while maintaining circuit density.
3Quantity of substance
If the dimension of connection via is reduced, then the circuit density is improved, but necking and open circuits occur
Solution Approach 1:
The patent applies preliminary action by performing hole expansion processing on connection vias along the width direction before lithography. The dimension expansion amount is determined based on the current lithography process window to ensure that the enlarged connection via maintains adequate dimensions throughout the manufacturing process. This prevents necking and open circuits while allowing the original via dimensions to be reduced for higher circuit density.
Data Source
AI summary
An optical proximity effect correction method for layout of metal lines and vias, includes: obtaining original layout of metal lines and vias; expanding each connection via in the width direction to form an enlarged connection via; translating each influencing metal line segment a certain distance away from the interconnection metal line along the width direction to form a preprocessed layout of metal lines and vias; and performing optical proximity correction on the preprocessed layout of metal lines and vias to obtain a corrected layout of metal lines and vias.