Semiconductor Pattern Position Monitoring for Ultrafine Alignment Errors
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Solution Overview
Problem
Existing methods for inspecting ultrafine patterns on semiconductor substrates are limited by the inability to accurately account for minute misalignments due to stage and pattern inaccuracies, particularly in ultrafine semiconductor manufacturing processes.
Innovation Solution
A measurement position monitoring apparatus that includes a pattern extractor, calculator, comparator, and position error calculator to determine the position error between a target point within an extracted pattern and a reference point, using image processing to adjust the stage position for improved alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inspection methods using align keys are used, then the inspection process is simple, but the measurement precision deteriorates due to minute misalignment of stage or patterns in ultrafine semiconductor manufacturing
Solution Approach 1:
The patent replaces the mechanical align key method with an image processing-based measurement system. The apparatus captures images of patterns on the substrate, extracts pattern information through image processing, and calculates position errors computationally, eliminating the need for physical align keys and mechanical alignment procedures.
Solution Approach 2:
The patent introduces an image processing unit as an intermediary between the substrate and the measurement system. By capturing optical images and processing them through pattern extraction and coordinate calculation algorithms, the system mediates the measurement process to achieve high precision without direct mechanical contact or alignment.
2Manufacturing precision
If the inspection method does not account for stage misalignment, then the inspection process is fast, but the manufacturing precision deteriorates due to uncorrected position errors in ultrafine patterns
Solution Approach 1:
The patent performs preliminary measurement of position errors using the image processing system before the actual pattern inspection or manufacturing steps. By calculating the position error between the measured pattern coordinates and design coordinates in advance, the system enables pre-compensation for stage misalignment, ensuring manufacturing precision without adding time during critical manufacturing steps.
3Measurement precision
If align keys are used for pattern inspection, then the ease of operation is high, but the measurement precision deteriorates due to inability to detect minute misalignment in ultrafine patterns
Solution Approach 1:
The patent replaces the mechanical align key system with an automated image processing system that captures substrate images, extracts pattern coordinates, and calculates position errors computationally. This substitution maintains operational simplicity through automation while achieving the measurement precision required for ultrafine semiconductor patterns.
Solution Approach 2:
The measurement system performs self-alignment and self-measurement by automatically capturing images, extracting pattern information, and calculating position errors without requiring external align keys or manual intervention. The system serves itself by using the substrate's own patterns as reference points for measurement.
Data Source
AI summary
A measurement position monitoring apparatus and a method of operating the same are provided. The method of operating the measurement position monitoring apparatus may include extracting a pattern from an image associated with a substrate, wherein the pattern is a bounded pattern; calculating a position of a target point within the extracted pattern; comparing the target point with a reference point; and calculating a position error in the target point.