Platinum–Copper Defects in Silicon

Abstract

The interaction of interstitial Copper (Cui) with substitutional platinum impurities (Pts) in n‐type FZ silicon wafers is studied by deep level transient spectroscopy (DLTS) and Laplace DLTS. Copper is introduced into silicon, which is Pt doped during growth, using chemo‐mechanical polishing (CMP) at room temperature in a copper‐contaminated slurry. After the CMP process, four new levels i.e., E80, E131, E147, and E271 are observed. These levels are only observed in Pt‐doped samples. From an analysis of the depth profiles of the new levels, it is ruled out, that the levels belong to different charge states of the same defect. The sum of concentrations of all depth profiles give a constant concentration of about 3 × 1014 cm−3, which corresponds to the total PtS concentration in the samples. Therefore, the new levels are attributed to several different defects which contain one substitutional Pt and several (1–4) interstitial Cu atoms.