SEM Fourier Pattern Measurement for Large-Area Wafer Repeats

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Solution Overview

Problem

Existing semiconductor manufacturing technologies face challenges in accurately and efficiently acquiring information about nanometer-level fine wafer patterns on semiconductor surfaces, necessitating improved methods for pattern measurement.

Innovation Solution

A semiconductor pattern measurement device and method utilizing a scanning electron microscope (SEM) with a processor to obtain SEM images, perform two-dimensional Fourier transforms, and merge images to determine the repetition period of repetitive patterns on wafer surfaces.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high-resolution SEM imaging is used to accurately measure nanometer-level patterns, then measurement precision is improved, but the measurement area is limited and measurement time increases

Engineering Contradiction:

Improvepattern measurement accuracyVSAvoidmeasurable pattern area

Core Design Contradiction:

Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent divides the wafer surface into multiple measurement regions and captures SEM images at different resolutions for different areas. High-resolution imaging is applied to specific regions of interest while lower-resolution imaging covers larger areas, enabling comprehensive measurement of the entire wafer surface without requiring uniform high-resolution imaging across all areas.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent introduces a multi-resolution imaging approach that operates across different dimensional scales. By capturing images at varying resolutions and using algorithms to process these multi-scale images, the system achieves both high measurement precision for nanometer-level patterns and comprehensive coverage of large wafer areas simultaneously.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Area of stationary object

If multiple SEM images are captured and processed to measure large areas, then measurement coverage is improved, but measurement time and processing complexity increase

Engineering Contradiction:

Improvemeasurable pattern areaVSAvoidmeasurement time

Core Design Contradiction:

Area of stationary objectVSLoss of time

Solution Approach 1:

The patent performs preliminary actions by capturing multiple SEM images at different resolutions and positions before final analysis. These pre-acquired images and their metadata are stored and organized, allowing rapid retrieval and processing during the measurement phase, thereby reducing overall measurement time while maintaining comprehensive area coverage.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a multi-resolution image database that serves as a copy of the wafer surface at different scales. This database can be rapidly queried and processed without requiring repeated physical measurement, significantly reducing measurement time for large area analysis while maintaining measurement coverage.

Inventive Principle:

Principle #26Copying

3Measurement precision

If electron beam intensity is increased to improve image quality, then image resolution is improved, but electron-induced damage to the wafer increases

Engineering Contradiction:

Improveimage resolutionVSAvoidelectron-induced damage

Core Design Contradiction:

Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies partial action by using lower electron beam intensity for general area mapping and reserved high-intensity imaging only for specific critical regions where maximum resolution is required. This selective approach reduces overall electron-induced damage to the wafer while maintaining the necessary image resolution for measurement purposes in key areas.

Inventive Principle:

Principle #16Partial or excessive action

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

The method enhances the accuracy and efficiency of pattern measurement by minimizing pattern distribution and reducing electron-induced damage, while enabling rapid measurement of large areas with reduced noise.

Implementation Method 1

obtaining a scanning electron microscope (SEM) image of a measurement target pattern on a surface of a wafer

Methodology Applied

Scientific EffectScanning electron microscopy: Electron Beam

Implementation Method 2

generating a first image by performing a two-dimensional Fourier transform on the SEM image

Methodology Applied

Scientific EffectFourier transform:

Data Source

PatentUS20250363619A1Semiconductor pattern measuremenet device and method of operation

Publication Date: 2025.11.27 SAMSUNG ELECTRONICS CO LTD

AI summary

Provided is a semiconductor pattern measurement method including obtaining a scanning electron microscope (SEM) image of a measurement target pattern on a surface of a wafer and including a repetitive pattern, generating a first image by performing a two-dimensional Fourier transform on the SEM image, generating a second image by merging a plurality of the first image, and obtaining information on repetition period of the repetitive pattern based on the second image.