PEEM—a spectromicroscopic tool for mc-Si surface evaluation

The photo emission electron microscope (PEEM) with its direct imaging of the sample surface is a convenient tool for fast evaluation of large sample areas. It is possible to handle samples with a size of 30 mm × 30 mm. EEM it is possible to visualise grain boundaries and crystal displacements without removing the native oxide. No special sample treatment is needed except chemical polishing of the sample surface and a HF-dip to obtain a thin (1…2 nm) oxide layer. ality of that oxide was proofed by high resolution photo electron spectroscopy (PES) at a synchrotron. The results were compared to native oxide on single-crystalline Si and no suboxides (e.g. SiO) were found. Our spectromicroscopic PEEM measurements show no difference in the oxide qualities of different grains and on grain boundaries or crystal displacements. Furthermore no difference in the binding energy of Si2p core levels were found. ition to grain boundaries other spot-like features were found on the sample surface. These could be identified in some cases as precipitation of Ca underneath the native oxide.