Multi-Layer Thickness Measurement via X-Ray Fluorescence and Transmission
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Solution Overview
Problem
Conventional methods for measuring the thickness of each layer in a multi-layer sample using X-rays face limitations, such as low intensity of fluorescent X-rays from deeper layers and the difficulty in distinguishing the thickness of individual layers from transmitted X-rays.
Innovation Solution
A method that involves irradiating a multi-layer sample with X-rays, detecting both fluorescent and transmitted X-rays, and using relational equations to calculate the thickness of each layer based on the intensity ratios of these X-rays, allowing for simultaneous satisfaction of multiple equations to accurately determine layer thicknesses.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the thickness measurement is performed based on fluorescent X-rays from deep layers, then the measurement range increases, but the detected intensity becomes too low to achieve accurate measurement
Solution Approach 1:
The patent combines fluorescent X-ray detection and transmitted X-ray detection into a unified measurement system. By merging these two detection methods, the system can simultaneously obtain information from both surface and deep layers, overcoming the limitation where fluorescent X-rays from deep layers become too weak to measure accurately alone.
Solution Approach 2:
The patent uses transmitted X-rays as an intermediary to obtain information about deep layers. Instead of relying solely on fluorescent X-rays from deep layers (which are too weak), the system uses transmitted X-rays that have passed through the entire sample as a mediator to infer the thickness of deep layers, thereby extending the measurement range while maintaining accuracy.
2Volume of moving object
If the thickness measurement is performed based on transmitted X-rays alone, then the measurement range increases, but the layer distinction becomes difficult due to signal superposition
Solution Approach 1:
The patent segments the measurement process into two independent parts: fluorescent X-ray detection for surface layer information and transmitted X-ray detection for overall thickness information. By segmenting the measurement function, the system can accurately distinguish between different layers - fluorescent X-rays provide layer-specific signals while transmitted X-rays provide bulk information, eliminating the superposition problem.
Solution Approach 2:
The patent adds another dimension to the measurement by simultaneously detecting both fluorescent X-rays (energy-specific, layer-specific) and transmitted X-rays (intensity-based, bulk). This dimensional expansion allows the system to differentiate between layers by combining layer-specific fluorescent signals with overall transmitted intensity data, making layer distinction possible even in thick multi-layer samples.
3Ease of operation
If conventional single-method measurement is used, then the measurement process is simple, but the ability to measure thick multi-layer samples is limited
Solution Approach 1:
The patent merges fluorescent X-ray detection and transmitted X-ray detection into a single integrated measurement process. The system irradiates the sample with X-rays and simultaneously detects both fluorescent and transmitted X-rays, then processes this combined information to measure the thickness of each layer. This merging enables the measurement of thick multi-layer samples while maintaining operational simplicity through automated multi-parameter analysis.
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 method enables the measurement of larger thicknesses and more accurately determines the thickness of each layer in a multi-layer sample, overcoming the limitations of conventional techniques.
Implementation Method 1
detecting fluorescent X-rays generated from the sample
Implementation Method 2
detecting transmitted X-rays that have passed through the sample
Data Source
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AI summary
There are provided a thickness measurement method, an X-ray analysis apparatus, an information processing apparatus, and a computer program that can measure the thickness of each layer of a multi-layer sample, which has been difficult to measure using conventional techniques. In the thickness measurement method, a sample including a plurality of layers is irradiated with X-rays so that the X-rays pass through the plurality of layers, fluorescent X-rays generated from the sample are detected, transmitted X-rays that have passed through the sample are detected, a first relational equation that expresses a relationship between the intensity of the detected transmitted X-rays and the thickness of each layer and a second relational equation that expresses a relationship between the theoretical intensity ratio of the fluorescent X-rays and the transmitted X-rays corresponding to the thickness of each layer and the intensity ratio of the detected fluorescent X-rays and the detected transmitted X-rays are created, and the thickness of each layer that simultaneously satisfies the first relational equation and the second relational equation is calculated.