RF magnetron sputter deposition and electrical properties of La and Y doped SrTiO3 epitaxial films

• Published in: Materials & design Vol. 179; p. 107888
• Main Authors: Guo, Chen-Yuan, Qi, Xiaoding
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 05.10.2019; Elsevier
• Subjects: Oxide electrode; RF magnetron sputtering; SrTiO3; Strontium titanate; RF magnetron sputtering; SrTiO3; Strontium titanate; Oxide electrode
• ISSN: 0264-1275; 1873-4197
• DOI: 10.1016/j.matdes.2019.107888

La and Y doped SrTiO3 (STO) thin films were grown on (100) oriented pure STO single crystal substrates by the RF magnetron sputter technique. The La/Y doped layer is intended for use as bottom electrode for epitaxial growth of various functional oxide films. The results showed that one of the crucial deposition parameters to achieve the epitaxial growth of La/Y doped STO films with a pure phase and good electrical conductivity was sputter power, which must exceed 120 W. The conductivity of the grown films increased with the increase in sputter power and the La0.1Sr0.9TiO3 (LSTO) films deposited at 200 W had the highest conductivity of 292 S/cm. This was ascribed to the increased percentage of Ti3+ ions in the sputtered films, which was confirmed by the X-ray photoelectron spectroscopy. LSTO films deposited at 130 W were (100) oriented but the increased sputter power promoted the growth of a second texture, i.e. (110). On the other hand, Y0.08Sr0.92TiO3 (YSTO) films were able to keep the unique (100) texture in the films deposited over a range of sputter powers up to 200 W, although the conductivity of YSTO was lower, which was 98.0 S/cm for the films sputtered at 200 W. [Display omitted] •Thin films of La/Y doped SrTiO3 were deposited on pure SrTiO3 by sputtering.•The doped films sputtered at over 120 W showed good electrical conductivity.•Conductive Y-SrTiO3 films were epitaxial with smooth surface good for electrode.•Ti3+ was detected in high-power sputtered films which was crucial for conduction.•Aliovalent doping and Ti3+ were charge-compensated by Sr2+ and O2– vacancy pairs.