Geometric Mask Rule Checks for Favorable SRAF Placement

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing lithography mask formation methods face challenges in accurately transferring sub-resolution assistant features (SRAFs) due to optical distortions, leading to inefficient pattern transfer and potential degradation of optical performance.

Innovation Solution

A method involving the generation of favorable and unfavorable zones based on diffraction maps, followed by geometric modifications of SRAFs to ensure they remain within favorable zones, optimizing optical performance while adhering to mask rules.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If SRAFs are modified through relocation, sizing, merging, or separation to pass mask rule check, then manufacturability requirement is improved, but optical performance may be degraded

Engineering Contradiction:

Improvemask rule check complianceVSAvoidoptical performance

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The patent performs preliminary actions by generating favorable and unfavorable zones before finalizing SRAF modifications. The favorable zones are pre-identified regions where SRAFs should be placed to ensure both mask rule compliance and optimal optical performance, allowing modifications to be made in advance rather than through trial-and-error adjustments

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The favorable and unfavorable zones act as intermediaries between the mask rule requirements and optical performance requirements. These zones provide a visual and spatial framework that guides SRAF modifications, serving as a mediator that translates manufacturing constraints into optical performance considerations

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of manufacture

If traditional methods are used to ensure accurate pattern transfer, then manufacturing process is simple, but time-consuming simulations are required

Engineering Contradiction:

Improvepattern transfer accuracyVSAvoidsimulation time

Core Design Contradiction:

Ease of manufactureVSLoss of time

Solution Approach 1:

The patent replaces time-consuming optical simulations with a geometric zone-based approach. Instead of performing complex simulations to determine optimal SRAF positions, the method uses diffraction map analysis to create favorable and unfavorable zones, which provides a quick and efficient way to guide SRAF placement without requiring extensive computational resources

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the accuracy of pattern transfer and maintains optical performance by geometrically managing SRAFs within favorable zones, reducing the need for time-consuming simulations.

Implementation Method 1

generating a diffraction map from the target pattern

Methodology Applied

Scientific EffectDiffraction: Diffraction

Data Source

PatentUS12406130B2Geometric mask rule check with favorable and unfavorable zones

Publication Date: 2025.09.02 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes generating a diffraction map from a plurality of target patterns, generating a favorable zone and an unfavorable zone from the diffraction map, placing a plurality of sub-resolution patterns in the favorable zone, and performing a plurality of geometric operations on the plurality of sub-resolution patterns to generate modified sub-resolution patterns. The modified sub-resolution patterns extend into the favorable zone, and are away from the unfavorable zone.