离子束合成的钇硅化物结构相变研究

Structural phase transformation in yttrium silicide prepared by ion beam synthesis

为了获得高品质的欧姆接触和线路连接材料,利用离子注入方法在n型单晶Si(111)基底上制备了钇硅化物,并对其在高真空下红外光辐照处理过程中的结构相变进行了研究.X射线衍射测量表明,在Y离子注入过程中已形成了部分六方相YSi2,800℃下红外光辐照处理30min后YSi2呈现出择优结晶取向.从辐照过程中原位测量样品的方块电阻变化发现,当温度升至160℃时,Y与Si反应首先形成了斜方相YSi.YSi/YSi2的相转变出现在240°C,随温度的进一步升高,Y原子完全与Si原子发生反应,形成了结晶取向良好的六方相YSi2.

To develop advanced interconnect materials with longer lifetimes and lower resistivities for use in integrated circuits, yttrium silicide layers were formed by implantation of 100 keV yttrium ions with a doses of 1×10^(18) cm^(-2) into (111) oriented n-type silicon wafers. The structural phases of the compound layers have been characterized by X-ray diffraction. It was shown that YSi_2 phase was formed during the implantation and a subsequent infrared-irradiation annealing of the samples under 800 ℃ for 30 min led to a (101) preferential growth. The in situ measurement of in situ sheet resistance during infrared-irradiation showed that the reaction between Y and Si occurs at a temperature of 160 ℃, while the phase transformation from YSi to YSi_2 takes place at 240 ℃.