钇硅化物的合成及相变研究

Ion Beam Synthesis and Electrical Properties Study of Yttrium Silicide

利用离子注入的方法在Si（111）衬底上制备出了具有六方结构的稀土硅化物YSi2埋层,并对其进行了结构及电学特性的研究.钇注入剂量为1×1018Y+cm-2,注入能量为100keV.利用X射线衍射（XRD）及卢瑟福背散射技术（RBS）得到了注入样品的结构相.结果显示,在对衬底Si进行Y离子注入的过程中就已经形成了YSi2相,在随后的红外光辐照退火过程中,样品呈现出了取向生长的趋势.利用RBS的测量分析了注入层中的Y离子在样品不同深度处的浓度分布.利用四探针法对刚注入的样品进行了红外光辐照过程中的原位方块电阻测量,结果显示,当退火温度升到160℃时,样品中形成了斜方的YSi亚稳相;而240℃则对应着YSi-YSi2的相转变点。

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℃.