The Mechanisms of Iron Gettering in Silicon by Boron Ion‐Implantation

Abstract

Boron implantation into silicon offers a unique system for studying the gettering mechanisms of Fe. The effectiveness of the gettering increases as the high‐energy B ion implantation dose changes from 4E12 to , decreasing the Fe concentration in the near surface region to below the deep level transient spectroscopy detection limit of . Fermi level‐induced Fe solubility enhancement and Fermi level‐controlled Fe‐B pairing combine to produce a relative partitioning for Fe as high as 106, for temperatures less than 400°C, in high B‐doped implanted regions adjacent to regions of low B bulk doping. Comparison studies show that in the time‐temperature regimes typical of Si device fabrication, B gettering is more effective than gettering produced by Si implantation damage and more effective than trapping by a neutral impurity such as C.