射频功率和衬底温度对碳化锗膜中sp3杂化碳原子的影响

ncreasing sp3 hybridized carbon atoms in germanium carbide films by increasing RF power and substrate temperature

利用磁控溅射方法以CH4和Ar的混合放电气体溅射单晶Ge靶制备碳化锗(Ge1-xCx)薄膜,通过XPS、Raman和Nanoindentation等表征手段系统地研究了射频功率和衬底温度对所获薄膜成分、键合结构及力学性质的影响。研究发现:射频功率和衬底温度的增加均能提高膜中的Ge含量,这分别归因于Ge溅射产额的增加以及含碳基团在衬底上脱附作用的增强。Ge含量的增加促进了sp2C-C键转变为sp3Ge-C键,进而显著提高了膜中sp3杂化碳原子的相对含量并改善了Ge1-xCx薄膜的硬度。这些结果表明:提高射频功率和衬底温度是制备富含sp3C的硬质碳化锗薄膜的有效途径。

Ge1-xCx films was prepared by RF reactive sputtering a pure Ge （111） target in a CH4/Ar mixture discharge. The effect of RF power and substrate temperature on the film composition, bonding structure and mechanical properties was systematically studied by means of XPS, Raman and Nanoindentation. The study showed that the increase of RF power and substrate temperature could improve Ge contents in the films, which was attributed to the increase of Ge sputtering yield and enhancemet of carbon-containing groups desorption from the substrate. The raise of Ge content promoted the change of sp2 C-C bonds to sp3 C-Ge bonds, thereby significantly improving the relative contents of sp3 hybridized carbon atoms in the films and the hardness of Ge1-xCx films. This investigation suggests that the hard Ge,_xCx films rich in sp3 hybridized carbon atoms can be prepared via increasing RF power or substrate temperature during deposition.