Metrology Parameter Reconstruction Through X-Ray–EUV Data Matching
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Solution Overview
Problem
Existing metrology techniques struggle to accurately measure small features in integrated circuits due to the use of wavelengths that are not available or usable for metrology, leading to inaccurate measurements and indirect evidence of product structures, especially in multiple patterning processes and pitch-multiplication scenarios.
Innovation Solution
A method involving the use of high-frequency radiation such as hard X-ray, soft X-ray, and EUV radiation for parameter reconstruction, combined with decomposition methods like Fourier analysis and weight matrix application, to directly measure and extract features from substrates, including vertically stacked nanosheets and gate all around transistors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If visible or near-infrared radiation is used for metrology measurements, then the measurement apparatus can operate with available radiation sources, but the pitch of the grating must be much coarser than the actual product structures, leading to indirect and inaccurate measurements
Solution Approach 1:
The patent changes the radiation wavelength parameter from visible/near-infrared to hard X-ray, soft X-ray, or EUV wavelengths. This parameter change enables the measurement apparatus to directly resolve small product structures without requiring coarse grating pitches, thereby simultaneously improving measurement accuracy and adaptability to small features.
2Measurement precision
If hard X-ray, soft X-ray, or EUV radiation is used for metrology, then small features can be directly measured with high precision, but such wavelengths are not normally available or usable for metrology
Solution Approach 1:
The patent introduces a radiation source generator as an intermediary component that converts available radiation (such as optical or infrared radiation) into hard X-ray, soft X-ray, or EUV radiation through processes like Compton scattering or photoelectric effect. This intermediary enables the use of high-energy radiation for metrology while circumventing the unavailability of direct high-energy radiation sources.
3Ease of manufacture
If known scatterometers use light in visible or near-infrared wave range, then the measurement system is simpler and radiation sources are more available, but the wavelength is not suitable for measuring small features defined using deep ultraviolet, extreme ultraviolet or X-ray radiation
Solution Approach 1:
The patent fundamentally changes the radiation wavelength parameter from visible/near-infrared to hard X-ray, soft X-ray, or EUV wavelengths. This parameter change aligns the measurement wavelength with the fabrication wavelength (deep ultraviolet, extreme ultraviolet, or X-ray), enabling direct and accurate measurement of small features while maintaining system feasibility through the introduced radiation generation mechanisms.
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
Enables precise measurement of small structures by directly penetrating and resolving features, providing accurate parameter extraction and improved process control in semiconductor manufacturing.
Implementation Method 1
a measurement apparatus configured to irradiate radiation onto each of one or more structures on a substrate; obtaining measured data relating to at least one measurement
Implementation Method 2
use of high-frequency radiation such as hard X-ray, soft X-ray, and EUV radiation for parameter reconstruction
Implementation Method 3
extreme ultraviolet (EUV) radiation, having a wavelength within the range 4-20 nm
Data Source
AI summary
Disclosed is a method comprising: obtaining measured data relating to at least one measurement by a measurement apparatus configured to irradiate radiation onto each of one or more structures on a substrate: decomposing the measured data using a decomposition method to obtain multiple measured data components: obtaining simulated data relating to at least one simulation based on the one or more structures: decomposing the simulated data using the decomposition method to obtain multiple simulated data components: matching between at least a portion of the simulated data components and at least a portion of the measured data components; and extracting a feature of the substrate based on the matching of at least a portion of the simulated data components and at least a portion of the measured data components.