Hybrid Thin-Layer Metrology for IC Thickness and Composition
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Solution Overview
Problem
Current methods for determining the thickness and composition of thin layers in microelectronic devices, such as integrated circuits, are inadequate for advanced technologies where precise measurements are crucial for device performance, particularly as layer thicknesses decrease.
Innovation Solution
A hybrid metrology system combining optical measurements, XPS, and XRF data, analyzed using model-based fitting procedures to optimize geometrical and material composition parameters, allowing for precise determination of layer thickness and composition in multi-layer structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional measurement techniques (ellipsometry, electron probe, XPS, SIMS) are used to determine layer thickness and composition, then measurement capability is provided, but measurement precision is insufficient for advanced technologies with reduced layer thicknesses
Solution Approach 1:
The patent combines multiple independent measurement techniques (optical OCD measurements, XPS measurements, and XRF measurements) into a hybrid metrology system. Each technique measures different properties of the multi-layer structure, and their data are integrated through model-based fitting procedures to achieve precise determination of layer thickness and composition that exceeds the capability of any single technique alone.
Solution Approach 2:
The patent creates a composite measurement approach by integrating data from three different measurement modalities (optical, photoelectron spectroscopy, and fluorescence spectroscopy). This composite measurement strategy leverages the complementary strengths of each technique to achieve superior measurement precision for thin layers in advanced integrated circuits.
2Length of moving object
If layer thickness is reduced to enable smaller integrated circuits, then device scaling is achieved, but measurement difficulty increases
Solution Approach 1:
The patent merges three independent measurement systems to tackle the measurement of ultra-thin layers. The optical OCD tool provides geometrical constraints, XPS provides element-specific photoelectron signals, and XRF provides fluorescent x-ray signals. The combination of these measurements enables accurate characterization of layers that are too thin to be reliably measured by any single technique.
Solution Approach 2:
The patent introduces model-based fitting procedures as an intermediary that processes and integrates data from the three measurement techniques. These models translate the raw measurement data into accurate determinations of layer thickness and composition, bridging the gap between the measurements and the physical parameters of interest.
3Loss of information
If multiple independent measurement techniques are performed on the same structure, then comprehensive data is obtained, but data interpretation complexity increases
Solution Approach 1:
The patent merges the data interpretation processes of optical OCD, XPS, and XRF measurements into a unified model-based fitting framework. This integrated approach simultaneously analyzes all three data sets to determine geometrical and material composition parameters, reducing the complexity that would arise from separately interpreting each measurement type.
Solution Approach 2:
The patent develops a universal data interpretation model that handles multiple measurement types (optical, photoelectron, fluorescent) within a single analytical framework. This multi-functional model can process different measurement modalities and extract comprehensive information about layer structure and composition, simplifying the overall interpretation process.
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 accurate and precise measurement of layer thickness and composition, improving the interpretation of data from optical, XPS, and XRF measurements, thereby enhancing the accuracy of microelectronic device characterization.
Implementation Method 1
an optical data analyzer module configured and operable to analyze said data indicative of the optical measurements and generate geometrical data indicative of one or more geometrical parameters of the multi-layer structure
Implementation Method 2
Angle-resolved XPS uses photoelectron spectroscopy to determine a thickness and/or composition of a layer or multiple layers. Photoelectron spectroscopy bombards a sample with photons having a specific wavelength (here, x-ray photons), which excite the atoms of the sample to generate a photoelectron having a characteristic energy for the sample.
Implementation Method 3
an x-ray fluorescence spectroscopy (XRF) measurement tool configured to perform XRF measurements on said IC and generate XRF measured data
Data Source
AI summary
A monitoring system and method are provided for determining at least one property of an integrated circuit (IC) comprising a multi-layer structure formed by at least a layer on top of an underlayer. The monitoring system receives measured data comprising data indicative of optical measurements performed on the IC, data indicative of x-ray photoelectron spectroscopy (XPS) measurements performed on the IC and data indicative of x-ray fluorescence spectroscopy (XRF) measurements performed on the IC. An optical data analyzer module analyzes the data indicative of the optical measurements and generates geometrical data indicative of one or more geometrical parameters of the multi-layer structure formed by at least the layer on top of the underlayer. An XPS data analyzer module analyzes the data indicative of the XPS measurements and generates geometrical and material related data indicative of geometrical and material composition parameters for said layer and data indicative of material composition of the underlayer. An XRF data analyzer module analyzes the data indicative of the XRF measurements and generates data indicative of amount of a predetermined material composition in the multi-layer structure. A data interpretation module generates combined data received from analyzer modules and processes the combined data and determines the at least one property of at least one layer of the multi-layer structure.