Liquid Particle Analysis of Metal Materials
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Solution Overview
Problem
Conventional methods for analyzing impurities in metallic materials, such as physical vapor deposition target materials, are labor-intensive, prone to inaccuracies due to particle agglomeration during filtering, and limited in detecting particles smaller than 2 microns, making them unsuitable for high-purity metal applications in semiconductor fabrication.
Innovation Solution
A method involving dissolving a portion of the metal material in an acid-comprising liquid and subjecting the sample to an incident laser beam to detect light scattering, allowing for accurate counting of particles smaller than 20 microns without filtering, using a liquid particle counter like the LIQUILAZ®, which is more efficient and less labor-intensive.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional dissolution and filtering techniques are used to analyze impurities in metal materials, then the analysis process can be performed with simple equipment, but particle agglomeration occurs during filtering giving inaccurate size and number data
Solution Approach 1:
The invention extracts only the necessary function of particle detection from the conventional dissolution-filtering-imaging process. By using light scattering detection on dissolved metal samples, it eliminates the filtering step that causes particle agglomeration while retaining the ability to detect and quantify impurity particles accurately.
Solution Approach 2:
The invention replaces the mechanical filtering and optical imaging system with a light scattering detection system. Instead of physically filtering particles and imaging them with microscopy, the system uses laser light scattering to detect particle presence and size, eliminating mechanical interference with particle distribution.
2Measurement precision
If conventional imaging systems are used to measure particles, then the system structure is simple, but the system is limited to detecting particles having a size greater than about 2 microns
Solution Approach 1:
The invention changes the detection parameter from direct optical imaging to light scattering measurement. This parameter change enables detection of much smaller particles (down to sub-micron sizes) because light scattering is sensitive to particle size and concentration in a different regime than direct imaging, allowing detection below the 2-micron limit of conventional systems.
3Productivity
If conventional dissolution and filtering techniques are used for impurity analysis, then the process requires minimal specialized equipment, but the process is relatively labor and time intensive
Solution Approach 1:
The invention enables continuous analysis by dissolving metal samples in acid and immediately analyzing the resulting solutions with light scattering detection. This eliminates the batch processing nature of conventional filtering and imaging methods, allowing for faster throughput and reduced analysis time while maintaining measurement accuracy.
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 precise detection and quantification of impurities in high-purity metal materials, improving the accuracy and efficiency of determining material suitability for semiconductor fabrication by correlating particle counts with target performance, even for extremely high-purity targets with small particle sizes.
Implementation Method 1
The liquid sample is subjected to an incident laser beam and light scattered from the sample is detected
Data Source
AI summary
The invention includes a method of detecting impurities in a metal-containing article. A portion of metal material is removed from a metal article and is solubilized in an acid or base-comprising liquid to produce a liquid sample. The liquid sample is subjected to an incident laser beam and light scattered from the sample is detected. The invention includes a method of analyzing a physical vapor deposition target material. A portion of target material is removed from the target and is rinsed with an acid-comprising solution. The portion of target material is dissolved to produce a liquid sample. The sample is subjected to an incident laser beam and scatter of the laser beam is detected to determine the number of particles present in the sample within a particular size range.