Curvature-Based Etch Bias Modeling for Semiconductor Pattern Accuracy

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Solution Overview

Problem

Existing etch simulation models fail to account for the influence of in-plane curvatures of wafer patterns on etch bias directions, leading to inaccuracies in predicting etch effects and subsequent patterning processes.

Innovation Solution

A simulation model that determines etch bias directions based on the curvatures of substrate patterns, considering both local and adjacent curvatures, to improve the accuracy of etch effect predictions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If existing etch simulation models use uniform etch bias directions perpendicular to contour, then the model complexity is low and easy to implement, but the manufacturing precision of etch effect prediction deteriorates

Engineering Contradiction:
Improveetch effect prediction accuracyVSAvoidsimulation model complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies local quality by making the etch bias direction variable at different locations on the contour based on local curvature characteristics. Instead of using a uniform perpendicular direction, the model calculates location-specific etch bias directions that account for variations in curvature, thereby improving prediction accuracy while managing model complexity through localized adjustments rather than complete model redesign

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent changes the parameter of etch bias direction from a fixed perpendicular orientation to a variable orientation determined by curvature calculations. By introducing curvature as a determining parameter for etch bias direction, the model adapts to local geometric variations in the contour, improving manufacturing precision without requiring fundamentally new simulation architecture

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If curvature-based etch bias direction determination is implemented, then the manufacturing precision of pattern contour prediction is improved, but the calculation complexity and processing time increase

Engineering Contradiction:
Improvepattern contour prediction accuracyVSAvoidsimulation processing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent segments the contour into discrete locations where curvature calculations are performed. By dividing the continuous contour into manageable segments or sampling points, the model can calculate etch bias directions at specific locations without requiring continuous computation along the entire contour, thereby reducing overall processing time while maintaining prediction accuracy

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements partial action by calculating curvature and determining etch bias directions at selected locations along the contour rather than at every possible point. This selective approach provides sufficient accuracy for manufacturing predictions while significantly reducing the computational burden and processing time required for simulation

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP4433869B1Determining an etch effect based on an etch bias direction
Publication Date: 2025.08.27 ASML NETHERLANDS BV
  • EP4433869B1 patent drawingFigure 1
  • EP4433869B1 patent drawingFigure 2
  • EP4433869B1 patent drawingFigure 3

AI summary

An etch bias direction is determined based on a curvature of a contour in a substrate pattern. The etch bias direction is configured to be used to enhance an accuracy of a semiconductor patterning process relative to prior patterning processes. In some embodiments, a representation of the substrate pattern is received, which includes the contour in the substrate pattern. The curvature of the contour of the substrate pattern is determined, and an etch bias direction is determined based on the curvature by considering the curvatures of adjacent contour portions. A simulation model is used to determine an etch effect based on the etch bias direction for an etching process on the substrate pattern.