Growing LaAlO3/SrTiO3 interfaces by sputter deposition

• Published in: AIP advances Vol. 5; no. 6; pp. 067156 - 067156-11
• Main Authors: Dildar, I. M., Neklyudova, M., Xu, Q., Zandbergen, H. W., Harkema, S., Boltje, D., Aarts, J.
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 01-06-2015; AIP Publishing LLC
• Subjects: Epitaxial growth; Oxygen; Parameters; Perovskites; Power supplies; Pulsed laser deposition; Pulsed lasers; Radio frequency; Stoichiometry; Strontium titanates; Substrates; Thin films
• ISSN: 2158-3226; 2158-3226
• DOI: 10.1063/1.4923285

Sputter deposition of oxide materials in a high-pressure oxygen atmosphere is a well-known technique to produce thin films of perovskite oxides in particular. Also interfaces can be fabricated, which we demonstrated recently by growing LaAlO3 on SrTiO3 substrates and showing that the interface showed the same high degree of epitaxy and atomic order as is made by pulsed laser deposition. However, the high pressure sputtering of oxides is not trivial and number of parameters are needed to be optimized for epitaxial growth. Here we elaborate on the earlier work to show that only a relatively small parameter window exists with respect to oxygen pressure, growth temperature, radiofrequency power supply and target to substrate distance. In particular the sensitivity to oxygen pressure makes it more difficult to vary the oxygen stoichiometry at the interface, yielding it insulating rather than conducting.