Semiconductor Wafer Inspection via Representative Optical Parameter Selection
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Solution Overview
Problem
As semiconductor devices become increasingly integrated, existing inspection methods struggle to reliably detect defects due to process variations, leading to inefficiencies in fabrication processes and potential defects in the final products.
Innovation Solution
A semiconductor wafer inspection method and system that selects a representative optical parameter with a correlation greater than a threshold, using a sophisticated optical inspection system to scan patterns, detect defects by comparing reference and inspection values, and amplify defect signals to improve detection precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional inspection methods are used to scan all optical parameters, then comprehensive data is collected, but detection precision is insufficient due to process variations
Solution Approach 1:
The patent extracts only the representative optical parameter that has high correlation with pattern characteristics from the full set of optical parameters. This selective extraction reduces data complexity while maintaining detection precision by focusing on the most relevant parameter for defect detection.
Solution Approach 2:
The patent changes the inspection approach by selecting and monitoring a specific representative optical parameter instead of all optical parameters. This parameter selection based on correlation analysis with pattern characteristics optimizes detection precision while reducing computational complexity.
2Reliability
If multiple optical parameters are monitored, then more information is obtained, but inspection time increases
Solution Approach 1:
The patent extracts only the essential representative optical parameter that provides sufficient information for reliable defect detection. This extraction eliminates redundant parameter monitoring while maintaining inspection reliability through focused measurement of the most informative parameter.
Solution Approach 2:
The patent applies partial action by monitoring only the necessary representative optical parameter rather than all available parameters. This partial monitoring approach achieves adequate inspection reliability with reduced time investment by focusing on the critical parameter.
3Measurement precision
If inspection sensitivity is increased to detect subtle defects, then defect detection capability improves, but false detection rate increases
Solution Approach 1:
The patent applies local quality by selecting a representative optical parameter that specifically correlates with pattern characteristics and defect signatures. This localized focus on the most relevant parameter enables sensitive defect detection while reducing false detections caused by variations in other unrelated parameters.
Solution Approach 2:
The patent changes from monitoring all optical parameters to monitoring a selected representative parameter with high correlation to pattern characteristics. This parameter change enables the system to detect subtle defects with high sensitivity while maintaining low false detection rates by focusing on the most discriminative parameter.
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 more precise detection of defects, reducing the occurrence of defects during semiconductor device fabrication by selectively amplifying defect signals and improving the reliability of inspection methods.
Implementation Method 1
a light source configured to emit an incident light on the wafer, a detector configured to detect a reflected light from the wafer
Data Source
AI summary
Disclosed are methods of inspecting semiconductor wafers, inspection systems for performing the same, and methods of fabricating semiconductor devices using the same. A method of inspecting a semiconductor wafer including preparing a wafer including zones each having patterns, obtaining representative values for the patterns, scanning the patterns under an optical condition to obtain optical signals for the patterns, each of the optical signals including optical parameters, selecting a representative optical parameter that is one of the optical parameters that has a correlation with the representative values, obtaining a reference value of the representative optical parameter for a reference pattern, and obtaining a defect of an inspection pattern by comparing the reference value with an inspection value of the representative optical parameter for the inspection pattern.