High Frequency Electromagnetic Field Processing of Amorphous Si layers containing Nanoclusters Produced by Implantation of Metal Ions in Si(100) Matrix

The effect of high-frequency electromagnetic field (HFEMF) on the electrical properties of metal ion beam implanted silicon was studied. Silicon wafers, (100) oriented, were implanted with Zn+, Te+ or Bi+ with energy of 50keV and fluences from 1 · 1015 to 1 · 1017cm 2. Cross-sectional transmission electron microscopy analyses show an amorphous Si layer (a-Si) at the Si surface for the three types of implanted species. Te+ and Bi+ form metallic nanoclusters (NCs) in the a-Si at fluences P1016cm 2, while no NCs were observed for Zn+. Post-implantation treatment with 0.45MHz HFEMF leads to decreased sheet resistance values only for samples with formed NCs. Another technique, AC electrical conductivity measurements, was used at frequencies in the range of 1Hz–100kHz. A correlation between the NCs evolution (as a function of implantation fluence and post-implantation processing) and the samples impedance dependence on these frequencies was found. An explanation based on potential barriers and HFEMF effect on the NCs is given