SCANNING PROBE ANALYSIS OF DEFECTS INDUCED BY SLIGHT IRON CONTAMINATION ON THERMALLY OXIDIZED p-TYPE SILICON WAFERS

摘要

In this article, we have demonstrated the investigation of scanning probe microscopy on the defects induced by slight iron contamination on p-type Si wafers with ultrathin thermal oxide layer. Using scanning capacitance microscopy (SCM) associated with atomic force microscopy, it is revealed that iron contamination induces interface traps, which significantly perturb the depletion behavior of the silicon surface. Moreover, experimental results also indicate that iron contamination leads to the lifetime decrease and the density increase of minority carriers in the defect region. From the dC/dV-V profiles, the defect region with the highest density of the interface traps also has the highest density of the deep-level traps. At a proper dc bias, the defect region clearly exhibits an obvious contrast in the SCM images.