Defect Inspection Using Multi-Ratio SE-BSE Image Synthesis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing defect inspection methods using synthesized images of secondary electron (SE) and backscattered electron (BSE) images suffer from reduced sensitivity, making it difficult to detect defects that can only be visually recognized by either the SE or BSE image, especially with the miniaturization of semiconductor patterns.
Innovation Solution
A defect inspection apparatus and method that synthesizes SE and BSE images with multiple synthesis ratios to generate multiple inspection images, which are then logically operated to produce a synthesized inspection image, allowing for defect determination across various types of defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a synthesized image is used to detect defects, then various types of defects can be covered, but defect detection sensitivity decreases compared to using SE or BSE images separately
Solution Approach 1:
The patent divides the inspection process into multiple segments by generating multiple synthesized images with different synthesis ratios (e.g., first synthesized image with ratio a, second synthesized image with ratio b). Each synthesized image is then processed separately through defect inspection to generate corresponding inspection images. This segmentation allows each inspection image to maintain high sensitivity for specific defect types while the final composite result achieves comprehensive defect coverage across all types.
Solution Approach 2:
The patent introduces a new dimension to the inspection process by creating a multi-dimensional inspection image space. Instead of a single synthesized inspection image, the system generates multiple inspection images at different synthesis ratio levels, then combines them through logical operations (OR operation) to create a comprehensive synthesized inspection image. This dimensional expansion resolves the contradiction by allowing high sensitivity at each dimension while maintaining overall versatility.
2Measurement precision
If the synthesis ratio is adjusted to detect specific defect types, then detection sensitivity for that defect type improves, but the ability to detect other defect types deteriorates
Solution Approach 1:
The patent segments the inspection process into multiple independent inspection paths, each optimized for specific defect types through different synthesis ratios. The first synthesized image with synthesis ratio a is inspected to detect defects of type A, while the second synthesized image with synthesis ratio b is inspected to detect defects of type B. This segmentation allows each path to achieve high sensitivity for its target defect type without compromising the overall system's ability to detect multiple defect types through the combined results.
Solution Approach 2:
The patent creates a multi-functional inspection system where each synthesized inspection image serves multiple purposes. The first synthesized inspection image primarily detects defects visible in SE images while the second synthesized inspection image primarily detects defects visible in BSE images. However, both images contribute to the final comprehensive inspection result, making the system universal for detecting various defect types simultaneously.
3Adaptability or versatility
If multiple synthesized images with different synthesis ratios are generated and processed, then comprehensive defect inspection is achieved, but inspection time and processing complexity increase
Solution Approach 1:
The patent segments the inspection process into parallel operations that can be executed simultaneously. Multiple synthesized images with different synthesis ratios are generated in parallel, and defect inspection is performed on each synthesized image independently in parallel. This parallel segmentation allows the system to achieve comprehensive defect inspection coverage while minimizing total inspection time through concurrent processing of multiple images.
Solution Approach 2:
The patent maintains continuous useful action by efficiently chaining the inspection processes. After generating multiple synthesized images, the system continuously processes each image through defect inspection and combines the results through logical operations. The synthesis and inspection operations are performed in a continuous workflow rather than discrete sequential steps, maintaining productive activity throughout the inspection process and reducing idle time.
Data Source
AI summary
Provided are a defect inspection apparatus and a defect inspection method that can inspect various types of defects in a synthesized image. The defect inspection apparatus synthesizes a first detection signal from a first detector and a second detection signal from a second detector with a first synthesis ratio to generate a first synthesized image, and synthesizes the first detection signal and the second detection signal with a second synthesis ratio different from the first synthesis ratio to generate a second synthesized image. The defect inspection apparatus generates a first inspection image based on the first synthesized image and generates a second inspection image based on the second synthesized image. The defect inspection apparatus executes a logical operation on the first inspection image and the second inspection image to generate a synthesized inspection image. The defect inspection apparatus executes defect determination on the synthesized inspection image.