Focused Beam Scatterometry for Submicron Structure Characterization
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Solution Overview
Problem
Current metrology techniques face challenges in accurately measuring submicron structures and thin films in microelectronic devices, particularly due to the limitations of simple imaging as sample structure dimensions approach or exceed light wavelengths, requiring non-destructive, high-throughput methods for precise characterization.
Innovation Solution
A focused beam scatterometry system measures diffraction of incident light and compares the results to a predictive model based on idealized structures, utilizing additional metrology systems to modify and optimize measurements for accurate characterization of submicron structures and thin films.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If simple imaging techniques are used, then ease of operation is improved, but measurement precision deteriorates when sample structure dimensions approach or exceed light wavelengths
Solution Approach 1:
The patent replaces simple optical imaging with focused beam scatterometry, which uses diffraction and scattering of light to measure submicron structures. This substitution of measurement methodology enables precise measurement of dimensions smaller than the light wavelength while maintaining operational feasibility through automated data collection and analysis.
Solution Approach 2:
The patent changes the measurement parameter from direct imaging to analysis of scattered light intensity and polarization state. By measuring these optical parameters and comparing them to predictive models, the system achieves high precision measurements of submicron structures without requiring the structures to be resolvable by conventional imaging.
2Measurement precision
If focused beam scatterometry is used to measure submicron structures, then measurement precision is improved, but device complexity increases
Solution Approach 1:
The patent employs a focused beam scatterometry system that can measure multiple parameters (dimensional characteristics, thin film thickness, material properties) using a single integrated apparatus. The system uses a universal measurement approach based on diffraction and scattering theory that applies across different sample types and measurement scenarios, reducing the need for multiple specialized devices.
Solution Approach 2:
The patent introduces predictive models as an intermediary between the measurement system and the sample structures. These models translate the complex scattering patterns into extractable dimensional information, simplifying the data analysis process and reducing the computational complexity required to obtain precise measurements.
3Measurement precision
If multiple metrology systems are integrated, then measurement precision is improved through model modification, but device complexity increases
Solution Approach 1:
The patent merges multiple metrology measurements into a single integrated scatterometry system. By combining data from different measurement approaches (diffraction, scattering, and additional metrology systems) within one apparatus, the system achieves enhanced measurement precision while avoiding the complexity of coordinating separate measurement devices.
Solution Approach 2:
The patent implements feedback mechanisms where measurement results from additional metrology systems are used to modify and refine the predictive models. This iterative feedback process continuously improves measurement accuracy by adjusting model parameters based on actual measurement data, creating a self-optimizing measurement system.
4Loss of substance
If non-destructive measurement methods are used, then loss of substance is prevented, but measurement precision may be compromised for non-planar structures
Solution Approach 1:
The patent replaces contact-based mechanical measurement methods with optical scatterometry, enabling non-destructive measurement of submicron structures and thin films. The optical method measures diffraction and scattering patterns that encode dimensional information without physically contacting or altering the sample, thus preventing any loss of substance while maintaining measurement precision.
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
The system provides non-destructive, high-accuracy, and high-throughput characterization of submicron structures and thin films, enabling precise measurements of dimensions and thicknesses, even for non-planar structures, by analyzing the intensity and polarization state of scattered light.
Implementation Method 1
Diffraction of incident light is measured by a detector
Implementation Method 2
analysis of the intensity and/or the polarization state of the light scattered off the sample structure
Implementation Method 3
analysis of the intensity and/or the polarization state of the light scattered off the sample structure
Data Source
AI summary
A system for monitoring thin-film fabrication processes is herein disclosed. Diffraction of incident light is measured and the results are compared to a predictive model based on at least one idealized or nominal structure. The model and/or the measurement of diffracted incident light may be modified using the output of one or more additional metrology systems.