Abstract: A buried hexagonal AlB₂-type YSi₂ layer was formed by metal vapor vacuum arc implantation of 100keV
yttrium ions with a dose of 1×10¹⁸ Y⁺ cm^-2 into (111) oriented silicon wafers. The heterostructures were analyzed by X-ray
diffraction(XRD), Rutherford backscattering spectroscopy(RBS) and the four-point probe technique. The concentration profiles of Y implanted
into p-Si (111) were determined by RBS. The results of XRD and RBS show that YSi₂ compound can be formed directly during the ion
implantation, and behave a tendency of tropism growth in the process of following irradiation with infrared ray. The measurements of in-situ
sheet resistance during infrared irradiation annealing show that the crystallization of the YSi occurs at 160℃, while YSi-YSi₂
phases transformation temperature is 240℃.

Key words: yttrium silicide, In-situ sheet resistance, ion implantation