Investigation of room temperature electrical resistivities of $LaNiO3−δ$ thin films deposited by rf magnetron sputtering and high oxygen-pressure processing

Highly (100)-oriented electrically conductive $LaNiO3−δ$ (LNO) thin film with perovskite-type structure was deposited on Si(100) substrates by rf magnetron sputtering at substrate temperatures of 200, 300, 450, and $600°C$ with a series of 0%, 20%, 40%, and 60% oxygen partial pressures, respectively. The room temperature (RT) resistivity of LNO films decreases with decreasing substrate temperature at a fixed oxygen partial pressure and with increasing oxygen partial pressure at a fixed substrate temperature. The lowest RT resistivity of as-sputtered LNO thin films was about $5.3×10−4Ωcm$⁠. This value could be as low as $∼1.55×10−4Ωcm$ by postprocessing called high oxygen-pressure processing at $8MPa$ and is comparable to the lowest one, $1.5×10−4Ωcm$⁠, of epitaxial LNO thin film deposited on lattice-matched $SrTiO3$⁠, $LaAlO3$⁠, or sapphire single-crystal substrates.