SrTiOs (STO) thin films were deposited on p-Si(100) substrates at various substrate temperatures from 300℃ to 700℃ by radio frequency (RF) magnetron sputtering technique. Their structure and electrical properties were investigated. It was found that the transition from amorphous phase to polycrystalline phase occurred at the substrate temperatures 300-400℃. Their crystallinity became better when the substrate temperatures further increased. The dielectric and leakage current measurements were carried out by using the Si/STO/Pt metal-insulator-semiconductor (MIS) structures at room temperature. It was found that the fixed charge density decreased and both the interface trap density and the dielectric constant increased when the substrate temperatures were increased. The leakage current mechanisms for STO MIS structures with STO films prepared at 700℃ followed the space charge limited current (SCLC) under the low applied electric field and the Poole-Frenkel emission under the high one. In addition, the resistivity for films prepared at 700℃ was higher than 10^11Ω.cm under the voltage lower than 10V (corresponding to the electric field of 1.54×10^3kV.cm^-1). It suggested that the STO films prepared at 700℃ were suitable for acting as the insulator of metal-ferroelectric-insulator-semiconductor (MFIS) structures.
采用组合靶,利用射频磁控溅射在260℃的(111)Si片上面制备了不同Ni、La含量比的La Ni O薄膜。测试分析结果表明,在La含量较高时,薄膜为无定型结构,并且具有较大的电阻率。当Ni和La含量比>1∶1.44后,薄膜具有(100)择优取向的赝立方钙钛矿结构,同时具有金属导电特性。随着La过量的减少,晶面间距和面电阻都减小的很快,在Ni和La比例达到1∶1时,电阻率达到了最小值6.4Ω·μm,晶面间距也达到最小值0.389nm。随着Ni过量的增加,晶面间距和面电阻又逐步增大。在Ni过量较多时导致了NiO相和LNO(110)取向的出现。在晶面间距相同时,相对于La,Ni含量的过剩对薄膜导电性能具有较大的影响。文中对实验现象从LaNiO3薄膜的导电机理出发给出了比较合理的解释。