Preparation of conductive LaNiO3 thin films by using reactive RF magnetron sputtering with La and Ni metals

Conductive LaNiO3 (LNO) thin films were successfully prepared on SiO2/Si (100) substrates by using the reactive RF magnetron sputtering method. Instead of a LNO ceramic target, La metal chips and a Ni metal target were used to deposit the LNO films. The atomic ratio of La to Ni gradually increased as the number of La chip increased, and the change of the ratio was measured using an energy dispersive spectrometer (EDS). The sputtering was conducted for 6 La chips. The ratio of Ni to La decreased with increasing sputtering temperature, to 1 at 400 degreesC after which it increased. The LNO films on SiO2/Si (100) usually had a (100) orientation for the deposition temperatures characterized by X-ray diffraction (XRD) analysis. The preferred orientation of LNO was (100) for deposition temperatures between 300 degreesC and 500 degreesC. Below 300 degreesC, the peaks from the (100) orientation had very low intensities. The resistivity of sputtered LNO film was measured using a DC four-point probe after a 600 degreesC- annealing for 30 min, and the LNO film sputtered at 200 degreesC showed the lowest resistivity, 280 muOmegacm. The surface morphology of the LNO deposited at room temperature was very smooth. With increasing substrate temperature, the grain size gradually increased.