CORRELATION BETWEEN DLTS AND TRXFA MEASUREMENTS OF COPPER AND IRON CONTAMINATIONS IN FZ AND CZ SILICON-WAFERS - APPLICATION TO GETTERING EFFICIENCIES

Metals forming deep traps in Si such as Fe, Cu, and Ni, are detectable with deep level transient spectroscopy (DLTS). In the present work, we used a spin-on technique as contamination method, which guaranteed sets of silicon wafers with authentic samples of iron- and, respectively, copper-contamination, that showed impurity concentrations on the wafer surfaces in the range of 10(11) and 10(13) atoms/cm2. A correlation between total reflection x-ray fluorescence analysis and DLTS has also been successful. Monitoring the iron content by DLTS in the course of gettering processes, we determined external and internal gettering efficiencies. Our compelling results showed a limited gettering efficiency at the oxygen precipitate sites, due to the level of iron contamination.