溅射时氧分压对LaNiO_(3-x)薄膜性能的影响

Oxygen partial pressure dependence of the properties of sputtered LaNiO_3 films

在较低的衬底温度(2600C)和不同氧分压下,采用射频溅射在(111)Si衬底上制备出了具有(100)择优取向的LaNiO3薄膜。SEM分析表明薄膜具有光滑连续的表面和均匀的晶粒尺寸。I-V特性表明薄膜均具有金属导电性,且随着氧分压的增加,电阻率逐步降低并达到一个稳定值10Ω·μm。实验结果同时表明,随着氧含量的增加,Ni、La含量比单调增大,并且当溅射气氛中的氧气分压在20%～30%范围时,Ni、La含量比为1:1而且比较稳定。当氧气分压为30%时,薄膜的晶面间距达到最小值。制备LaNiO3薄膜的最佳氧气分压应该控制在30%左右。

Thin LaNiO3 films with (100) preferred orientation were deposited on (111)Si substrates at 260 0C successfully by RF- magnetron sputtering with a ceramic target. The grain size of the film is small and uniform, and the surface is smooth. The results also demonstrate that the films exhibit a metallic conductivity, and the resistivity decreases to a stable value of 10Ω · μ m as oxygen partial pressure increases. The minimum distance between two adjacent parallel planes normal to film surface is obtained as oxygen partial pressure is 30% . Meanwhile,as oxygen partial pressure increases, the content ratio of Ni to La increases, and when oxygen partial pressure is in the range of 20% ～ 30% the content ratio of Ni to La is of the stoichiometric composition. Therefore, the best condition for LNO deposition is 30% oxygen partial pressure.