In the manufacturing of megabit dynamic random access memories (4 M DRAMs) the influence of dry etching processes on refresh failures is often observed. A principal reason for refresh failures are leakage currents in the isolating p-n junction. The effects of intentional and reactive ion etching (RIE)-induced metal contamination on the leakage currents and diffusion currents measured in the Elymat have been systematically studied. It has been shown that this technique is a convenient and process relevant monitoring tool for RIE-induced contamination by Fe, Mo, Cu, and Ni with a spatial resolution capability.