Radiation resistance of Fe-Si compounds and its application

采用离子束溅射沉积（IBSD）方法对Si表面进行改性，在Si表面形成半导体β-FeSi_2层。结果表明，通过选择溅射刻蚀和热退火条件，在973 K下可以制备出厚度为100 nm的高度取向的β-FeSi_2薄膜，其外延关系为β-FeSi_2（100）// Si（100）。进一步的研究表明，通过优化衬底温度、溅射原子沉积厚度和靶材成分，在873 K的低温下也可以形成高取向的薄膜，或者可以使薄膜变厚.透射电子显微镜（TEM）观察表明，β-FeSi_2 / Si界面是原子级的平坦连续界面，这表明该硅化物可用于与Si衬底形成异质结以用于器件应用。此外，硅化物的表面被发现是高度抗氧化。初步研究了高能（> 100 MeV）重离子辐照对硅化物薄膜的影响，发现随着离子注量的增加，硅化物薄膜变成非晶态，没有观察到相变。光致发光测量被证明是有用的，以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.