Charged Particle Beam Apparatus Pattern Contour Inspection
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Solution Overview
Problem
Existing defect inspection methods for semiconductor wafers are unable to selectively detect defects that are not influential on product yield, and struggle to set inspection regions based on pattern shapes, leading to inefficiencies in throughput and accuracy.
Innovation Solution
A charged particle beam apparatus that extracts the contour of a pattern using a template image, sets the inspection region based on this contour, and compares images to detect defect candidates within the specified region, allowing for selective defect detection and classification.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If all different parts are detected as defects (method in Patent Document 1), then defect detection coverage is improved, but inspection accuracy for selective defect detection deteriorates
Solution Approach 1:
The inspection system segments defects into different categories based on their characteristics and significance. By dividing the defect detection task into multiple levels (all defects vs. significant defects), the system can first identify all potential defects broadly, then apply more precise classification to distinguish significant defects from noise, thereby resolving the contradiction between comprehensive coverage and selective accuracy.
Solution Approach 2:
The system applies different detection thresholds and analysis methods to different regions and defect types. Rather than using a uniform detection criterion across the entire wafer, the inspection adapts local quality standards based on pattern characteristics and defect locations, enabling selective detection of significant defects while maintaining overall coverage.
2Productivity
If inspection regions are not set based on pattern shapes, then inspection throughput is improved, but inspection accuracy for relevant defects deteriorates
Solution Approach 1:
The system performs preliminary extraction of pattern contours and predetermined defect region information before the actual defect detection process. By preparing these spatial references in advance, the inspection can quickly determine whether detected defects fall within significant regions, enabling fast throughput while maintaining accurate focus on relevant defects without examining every pixel in detail.
Solution Approach 2:
The patent introduces predetermined defect region information and pattern contour data as intermediary elements that mediate between the inspection system and the actual defects. These intermediaries serve as spatial guides that enable the system to rapidly filter and prioritize defect regions, achieving both high throughput and accurate detection of significant defects.
3Quantity of substance
If the number of detected defect candidates is increased, then defect detection coverage is improved, but identification of significant defects deteriorates
Solution Approach 1:
The system employs feedback mechanisms where predetermined defect region information and pattern contour data guide the defect detection and classification process. By continuously referencing these predetermined spatial patterns, the system can feedback-filter the large number of detected defect candidates, identifying which ones fall within significant regions and should be prioritized, thereby maintaining high detection coverage while preserving signal-to-noise ratio.
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
Enables selective detection and classification of defects on desired patterns, improving inspection throughput and aiding in yield improvement by focusing on relevant defects and their causes.
Implementation Method 1
a charged particle beam apparatus that extracts the contour of a pattern using a template image obtained on the basis of an image of a sample
Data Source
AI summary
For inspection of a pattern such as a semiconductor device, it is useful to selectively detect a defect on the specific pattern in order to estimate the cause of the occurrence of the defect. An object of the invention is to provide a charged particle beam apparatus capable of setting, on the basis of the shape of the pattern on a sample, a region to be inspected. The invention is characterized in that the contour of the pattern on the sample is extracted using a template image obtained on the basis of an image of the sample, the region to be inspected is set on the basis of the contour of the pattern, a defect candidate is detected by comparing the image to be inspected with a comparative image, and the sample is inspected using a positional relationship between the region to be inspected and the defect candidate included in the region to be inspected.