Enrichment of Metal Ions in Virgin Si-Surfaces

Beside the silicon feedstock material and the crystallization process, the wafering process can strongly influence the material quality. Especially surface contaminations are introduced in this process step, because a virgin silicon surface is produced for the first time. In this paper the influence of different metal ion contents in the surrounding medium (PEG200) on the surface contamination of oxidized silicon is studied with surface extraction ICP-MS. It can be shown that metal ions are strongly enriched in the wafer surface. Investigations of different cleaning procedures show their potential to remove the surface contaminations, which is essential for the production of high efficiency solar cells.