Hybrid Mask Filter for Semiconductor Lattice Strain Analysis

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Solution Overview

Problem

Existing methods for analyzing lattice strain in semiconductor devices face challenges in achieving high resolution and accuracy due to the trade-off between spatial resolution and noise levels in strain images, particularly when using cosine mask filters.

Innovation Solution

A method utilizing a hybrid mask filter based on a combination of Gaussian and Sigmoid functions, represented by F(x) = Ke^(-2r^2) + (1-K) * 1/(1+er), is applied to select peak frequencies in spectrum images, allowing for improved noise removal and spatial resolution through Fourier Transform and inverse Fourier Transform processes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If a cosine mask filter is used in existing commercial software for strain analysis, then the filtering process is simple and straightforward, but the spatial resolution of the strain image deteriorates and noise increases

Engineering Contradiction:
Improveease of filteringVSAvoidspatial resolution
Core Design Contradiction:
Ease of manufactureVSMeasurement precision

Solution Approach 1:

The patent changes the functional form of the mask filter from a cosine function to a hybrid function combining Gaussian and Sigmoid functions. This parameter change in the filter's mathematical representation enables simultaneous achievement of high spatial resolution and effective noise suppression, resolving the contradiction between simple filtering and measurement precision.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite mask filter by combining Gaussian function characteristics (noise suppression) and Sigmoid function characteristics (edge preservation) into a single hybrid function. This composite approach allows the filter to simultaneously achieve noise reduction and maintain spatial resolution, overcoming the limitations of using a single function type.

Inventive Principle:
Principle #40Composite materials

2Measurement precision

If the size of the cosine mask increases to improve spatial resolution, then the spatial resolution of the strain image improves, but noise increases

Engineering Contradiction:
Improvespatial resolutionVSAvoidnoise
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a new functional form with adjustable parameters (sigma for Gaussian width, threshold for Sigmoid transition) that independently control noise suppression and resolution characteristics. By optimizing these parameters, the system achieves high spatial resolution without the noise penalty associated with increasing cosine mask size.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The hybrid filter combines the noise-suppressing Gaussian component with the edge-preserving Sigmoid component, creating a composite filtering mechanism that selectively reduces noise while maintaining spatial resolution. This composite structure allows simultaneous optimization of both contradictory properties.

Inventive Principle:
Principle #40Composite materials

3Object-generated harmful factors

If a larger mask size is used to reduce noise, then noise levels decrease, but spatial resolution deteriorates

Engineering Contradiction:
Improvenoise levelVSAvoidspatial resolution
Core Design Contradiction:
Object-generated harmful factorsVSMeasurement precision

Solution Approach 1:

The patent uses parameter optimization to achieve the desired balance between noise reduction and resolution. By adjusting the sigma parameter of the Gaussian component and the threshold parameter of the Sigmoid component, the system can achieve effective noise suppression while maintaining high spatial resolution, eliminating the need to increase mask size at the cost of resolution.

Inventive Principle:
Principle #35Parameter changes

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

This approach enables the generation of strain images with enhanced spatial resolution and reduced noise, allowing for more accurate analysis of lattice strain in semiconductor devices, thereby improving the analysis of stress effects on device performance.

Implementation Method 1

generating a spectrum image by performing a Fourier Transform on an image of a semiconductor device

Methodology Applied
Scientific EffectFourier Transform:

Implementation Method 2

generating a first strain image by performing an inverse Fourier Transform on the filtered spectrum image

Methodology Applied
Scientific EffectInverse Fourier Transform:

Data Source

PatentUS10410332B2Method of analyzing lattice strain of semiconductor device
Publication Date: 2019.09.10 SAMSUNG ELECTRONICS CO LTD
  • US10410332B2 patent drawing
  • US10410332B2 patent drawing
  • US10410332B2 patent drawing

AI summary

A method of analyzing lattice strain of a semiconductor device includes generating a spectrum image by performing a Fourier Transform on an image of a semiconductor device, providing a first hybrid mask filter t filter designed to select at least one peak frequency from the spectrum image, filtering the spectrum image using the first hybrid mask filter to generate a filtered spectrum image, and generating a first strain image by performing an inverse Fourier Transform on the filtered spectrum image.