Regensburg 2002 – wissenschaftliches Programm
HL 43.7: Vortrag
Freitag, 15. März 2002, 12:00–12:15, H14
Variable-Temperature Spreading-Resistance Profiling of Silicon and Germanium — •N.A. Stolwijk, S. Voß, and H. Bracht — Institut für Materialphysik, Universität Münster
We have developed the concept of variable-temperature spreading-resistance profiling (VT-SRP) for the characterization of electrical active impurities or defects in semiconductor crystals. Unlike conventional SRP systems, which are exclusively operated at room temperature, our home-built VT-SRP device allows for measurements at different temperatures typically ranging from 150 K to 360 K. VT-SRP is able to combine the accurate resolution of an impurity depth profile with a determination of the predominant impurity-related electronic level in the semiconductor bandgap. This novel feature was exploited on germanium crystals with diffusion-induced gold distributions. Another application concerns the depth profile analysis of foreign elements that occur in various defect configurations. This was demonstrated on Si samples diffused with sulfur or selenium since these impurities may be present as isolated atoms as well as pairs. Given the well-known energy levels of the two S or Se configurations in Si we were able to resolve not only the shape and depth of the diffusion profile but also the ratio of isolated atoms to pairs in the diffusion zone.