Pattern Inspection Apparatus Using Reference Outline Extraction
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Solution Overview
Problem
Current pattern inspection methods require significant processing for matching correspondence between outline images, leading to large processing circuitry and inefficiencies in defect inspection for ultrafine patterns on semiconductor wafers.
Innovation Solution
A pattern inspection apparatus and method that acquires measurement images using electron or laser beams, creates a reference outline from design pattern data, and extracts the outline of the figure pattern using starting points on the reference outline, eliminating the need for matching processing between two outline images.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If matching processing is performed to find correspondence between two outline images, then inspection accuracy is improved, but processing amount and circuitry size increase significantly
Solution Approach 1:
The patent applies preliminary action by pre-defining the search range for outline points based on design data before performing the actual outline extraction and comparison. The search range is determined in advance using design pattern information, which eliminates the need for complex matching processing to find correspondence between two outline images. This allows the system to directly compare extracted outlines with design data within the predetermined search range, reducing processing circuitry requirements while maintaining inspection accuracy.
2Measurement precision
If separate processing is performed for extracting outlines from design data and inspection images, then outline extraction accuracy is improved, but total processing amount increases
Solution Approach 1:
The patent merges the outline extraction process with the defect inspection process by extracting outlines from both design data and inspection images simultaneously using corresponding search ranges. Instead of performing separate extraction processes that would require extensive matching, the system extracts outlines in an integrated manner where the search range determined from design data is directly applied to the inspection image processing. This combining of operations maintains outline extraction accuracy while significantly reducing the total processing amount and improving productivity.
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
Reduces the amount of processing required for outline creation and defect inspection, enabling higher accuracy and efficiency in detecting defects on ultrafine patterns without the need for extensive matching processing.
Implementation Method 1
a measurement image acquisition mechanism configured to acquire a measurement image, which is a secondary electron image or an optical image of a figure pattern, from a substrate on which the figure pattern is formed by using electron beams or laser beams
Data Source
AI summary
According to one aspect of the present invention, a pattern inspection apparatus includes reference outline creation processing circuitry configured to create a reference outline of a reference figure pattern, which serves as a reference, by using pattern data of a design pattern that serves as a base of a figure pattern formed on a substrate; outline extraction processing circuitry configured to extract an outline of the figure pattern in the measurement image from the measurement image using, as starting points, a plurality of points that are positioned on the reference outline; and comparison processing circuitry configured to compare the reference outline with the outline of the figure pattern.