Growing LaAlO3/SrTiO3 interfaces by sputter deposition
I. M. Dildar,
M. Neklyudova,
Q. Xu,
H. W. Zandbergen,
S. Harkema,
D. Boltje,
J. Aarts
Affiliations
I. M. Dildar
Kamerlingh Onnes Laboratorium, Leiden University, The Netherlands
M. Neklyudova
National Center for High Resolution Microscopy, Kavli Institute for Nanoscience, Delft Technical University, Lorentzweg 1, 2628 CJ Delft, The Netherlands
Q. Xu
National Center for High Resolution Microscopy, Kavli Institute for Nanoscience, Delft Technical University, Lorentzweg 1, 2628 CJ Delft, The Netherlands
H. W. Zandbergen
National Center for High Resolution Microscopy, Kavli Institute for Nanoscience, Delft Technical University, Lorentzweg 1, 2628 CJ Delft, The Netherlands
S. Harkema
Faculty of Science and Technology and MESA+ Institute for Nanotechnology, University of Twente, 7500 AE Enschede, The Netherlands
D. Boltje
Huygens - Kamerlingh Onnes Laboratorium, Leiden University, The Netherlands
J. Aarts
Huygens - Kamerlingh Onnes Laboratorium, Leiden University, The Netherlands
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.
