Radiation resistance of Fe-Si compounds and its application

采用离子束溅射沉积（IBSD）方法对硅表面进行修饰，形成具有半导体性质的β-FeSi_2层。结果表明，通过精心选择溅射刻蚀和热退火条件，可以在973 K下制备出厚度为100 nm、外延关系为β-FeSi_2 100 // Si（100）的高取向β-FeSi_2薄膜。进一步的研究表明，高取向薄膜也可以在更低的温度下形成，即在873 K，或者可以通过优化衬底温度、溅射原子的沉积厚度和目标成分来制备更厚的薄膜。透射电子显微镜（TEM）图像显示，β-FeSi_2 / Si的界面是原子平面的、连续的，表明该硅化物可用于与硅衬底形成异质结。此外，发现硅化物表面具有很强的抗氧化性。初步研究了高能（bbb100 MeV）重离子（Xe离子）对硅化物膜的辐照效应，发现随着离子辐照量的增加，硅化物膜呈无定形，未发生相变。光致发光测量被证明是有用的，进一步阐明辐照对薄膜和衬底的影响，而不是说半导体硅化物层的光学性质。

Ion beam sputter deposition (IBSD) method was employed to modify the surface of Si surface by forming a semiconducting β-FeSi_2 layer. It was revealed that, by carefully choosing the sputter etching and thermal annealing conditions, a highly-oriented thin β-FeSi_2 film of 100 nm in thickness, with the epitaxial relationship of β-FeSi_2 100) // Si (100) can be fabricated at 973 K. Further investigation demonstrated that a highly-oriented film can be also formed at much lower temperature, i.e. at 873 K, or can be made thicker by optimizing the substrate temperature, deposited thickness of sputtered atoms and the target compositions.Cross-sectional transmission electron microscope (TEM) images showed that the interface of β-FeSi_2 / Si is atomically flat and continuous, which suggests that this silicide can be used to form heterojunction with Si substrate for device applications. In addition, the surface of silicide was found to be highly resistant to oxidation. Preliminary investigation on the irradiation effects on the silicide film using high-energy (> 100 MeV) heavy ion (Xe ion) revealed that the film became amorphous as the ion fluence was increased, and that no phase transformations could be observed. Photoluminescence measurement proved to be useful to further elucidate irradiation effects on the film and substrate, not to say the optical properties of semiconducting silicide layer.