Iron, Nickel and Copper Implantation into Silicon

Abstract

A study has been made of the structure and sheet resistivity of metal implanted silicon. The substrates used were (100) oriented single crystal silicon wafers. The iron, nickel and copper ion implantations were performed with doses ranging from 7.5×10¹⁶ to 5×10¹⁷ions/cm² at an energy of 150 keV. The depth profiles of implanted atoms were estimated by Rutherford Backcattering spectroscopy (RBS). The identification of silicides produced by implantation were performed by X-ray diffraction (XRD). The sheet resistivity measurements were carried out by using a four point probe method. The maximum concentration of implanted atoms for the highest dose samples existed near the silicon surface, and silicides composed of silicon and implanted metals were formed in the implanted layers. The sheet resistivity of iron and nickel implanted silicon decreased extremely with increasing the dose, but in the case of copper implantation it did not so. These results suggest that silicides can be formed in implanted layers without any thermal annealing, but all of metal implantations do not cause the resistivity to decrease.