High Purity Tungsten Trace Impurities Testing

High purity tungsten, which has high resistance to electron transport and high temperature stability, is capable of forming a stable silicide and is often used as a thin film in the electronics industry as a gate, connecting and barrier metal.

The determination of trace elements in high purity tungsten is an important criterion for evaluating the properties of high purity tungsten. The common methods for the determination of trace elements in high purity metals are spectral analysis, mass spectrometry analysis, neutron analysis, etc.

Ion exchange chromatography emission spectroscopy were used to analyze trace impurities in high purity tungsten, but generally need to convert the sample solution, sample dilution due to the conversion of the detection limit and the uncertainty increases, it is easy to introduce pollution so as to influence the final results.

With the improvement of material purity, the conventional spectral analysis and element analysis and sensitivity of neutron analysis can not meet the requirements of 6N tungsten powder analysis. Mass spectrometry is playing an increasingly important role in the detection of trace impurities in high purity tungsten.

The determination of inductively coupled plasma mass spectrometry (ICP-MS) is a new generation of trace analysis technology, which has the advantages of low detection limit and simultaneous analysis of multi elements. However, there is still a problem of the interference of the matrix effect. Beijing Research Institute of nonferrous metals to pre separation and enrichment technology, using matrix separation ion chromatography, reduce the interference of matrix of impurity detection, to purge solvent dissolving device can effectively reduce the oxide ICP-MS detection in the process of the yield of membrane, accurate determination of impurities in tungsten powder 6N.

Compared with the ICP-MS method, glow discharge mass spectrometry (GD-MS) can directly measure solid samples, and the surface contamination of samples can be eliminated by a pre sputtering process at a certain time. Ion source has strong ionization capacity, fast analysis speed, high sensitivity and high resolution. It can be used for qualitative or semiquantitative analysis of most elements in the periodic table without standard samples. At the same time, the loss of insoluble elements and the introduction of pollution are avoided in the process of ICP-MS method. It can be more effectively applied to the comprehensive analysis and detection of high purity tungsten in 6N and above. With the further improvement of instrument sensitivity, resolution and stability, GD-MS will be widely applied as a mass spectrometry method for direct analysis of ultra pure samples.

• < Prev
• Next >