Ultratrace Analysis

© Fraunhofer CSP
The ICP-MS is being loaded with samples.

We offer comprehensive chemical analysis for customers from the photovoltaic industry. The core area of our R&D services is ultra trace analysis in all relevant materials: silicon, silane, CIGS, quartz crucibles, saw slurry, etc. In addition to the determination of total concentrations down to the low ppb range, methods for locally resolved analysis are also available. Another focus is the chemical characterization of surfaces and boundary layers. Whether metals, dopants, organic contaminations or surface energy - all methods are adapted to the special purity requirements of semiconductor materials.

Depending on the customer's requirements, we offer both simple analytical services as well as root cause investigations and complex problem solutions.

Services

  • Ultra trace analysis in volume: quantitative determination of contaminations and dopants
  • Surface and interface analytics: quantitative determination of inorganic / organic contaminations and surface energy
  • Development of adapted analytical methods e.g. for process monitoring and quality control
  • Consulting and training on the subject of trace analysis
  • Rent-a-Scientist

Examples

© Fraunhofer CSP
Experimental CZ silicon crystal and vertical concentration profile of impurities (example: aluminum).

Ultra Trace Analysis in Solids

High purity of the starting materials is the basic requirement for high-performance solar cells and semiconductor components. This is countered by cost pressure on manufacturing processes. The highly sensitive quantitative determination of foreign elements in feedstock, crystals and wafers can help to ensure the necessary material quality and optimize energy-intensive processes.

© Fraunhofer CSP
Flow chart of the layer-specific element analysis.

Layer-specific Element Analysis

Processing steps such as sawing, cracking and grinding cause surface contamination, which can also migrate into deeper layers. A sensitive layer specific element analysis can help to find out where the contamination is located and how an efficient cleaning can be done. The analysis of wafers, lumps, granules or powder samples is carried out by layer-specific etching steps and subsequent ICP-MS analysis.

  • Wahl, S., Meyer, S., Hagendorf, C., Localization of inorganic impurities in silicon samples by sequential etching and ICP-MS detection, 6th International Conference on Silicon Photovoltaics, SiliconPV 2016 (on Sciencedirect)
     

© Fraunhofer CSP
Quantitative element analysis in CIGS solar cells.

Quantitative Elemental Analysis in CIGS Solar Cells

Quantitative element analysis is also interesting for manufacturers of CIGS solar cells. For quality control or process optimization, the matrix elements of the TCO, buffer and absorber layers as well as the trace elements contained therein can be analyzed layer-selectively. This is done by serial separation of the individual layers with suitable etching solutions and subsequent quantitative determination of the element concentration in the solutions using ICP-OES or ICP-MS. The method is suitable for all substrate types and it has been shown that the results are comparable with reference methods such as ToF-SIMS or XRF.

K. Kaufmann, S. Wahl, S. Meyer, E. Jarzembowski, C. Hagendorf : Quantitative Analysis of Matrix Elements and Sodium in Photovoltaic Cu(In, Ga)Se2 Thin Films by the Use of Time-of-Flight Secondary Ion Mass Spectrometry; 31st European Photovoltaic Solar Energy Conference and Exhibition 2015.