采用射频磁控溅射方法,在Si(111)和石英衬底上制备了Fe/Si亚层厚度比不同的多层膜。多层膜的总厚度为252nm,Fe/Si亚层厚度比分别为1nm/3.2nm、2nm/6.4nm和20nm/64nm。在850℃,Ar气气氛中退火2h后,Si衬底上的多层膜完全生成了β-FeSi2相。但石英衬底上同样Fe/Si亚层厚度比的多层膜除了生成β-FeSi2相,还生成了少量的ε-FeSi相。通过增加Si亚层的厚度至Fe/Si亚层厚度比为2nm/7.0nm,在石英衬底上也获得了单相的β-FeSi2薄膜,其光学带隙为0.87eV,表面均方根粗糙度为2.34nm。
Fe/Si multilayer thin films with different sublayer thickness ratios ( RFe/Si) were prepared by radio frequency magnetron sputtering on Si( 111) and quartz substrates. The films have the same total thickness of 252 nm while the RFe/Si is 1 nm/3. 2 nm,2 nm/6. 4 nm and 20 nm/64 nm,respectively. After annealing at 850 ℃ in Ar atmosphere for 2 h,all the multilayer films on Si ( 111) substrate completely formed β-FeSi2 film. For the same RFe/Si,β-FeSi2 phase and a small amount of ε-FeSi phase were formed on quartz substrates. By increasing the thickness of Si sublayer in the Fe/Si multilayer films to Fe ( 2 nm) / Si ( 7. 0 nm) ,a film with single phase of β-FeSi2 was obtained on the quartz substrate. The optical gap of the sample is 0. 87 eV and the surface root mean square roughness is 2. 34 nm.