Narrow growth window for stoichiometric, layer-by-layer growth of LaAlO3 thin films using pulsed laser deposition

• Structure properties of PLD grown homoepitaxial LaAlO3 films are investigated.
• Films grown at higher oxygen pressures (100–300 mTorr) have bulk-like structure.
• Films grown at low pressure (10−4–10−2 Torr) suffer from lattice expansion.
• Oxygen pressure during the growth can change the structure of LAO film.

We study the structure and surface morphology of the 100 nm homoepitaxial LaAlO3 films grown by pulsed laser deposition in a broad range of growth parameters. We show that there is a narrow window of growth conditions in which the stoichiometric, bulk-like structure is obtained while maintaining a 2-dimensional (2D) layer-by-layer growth mode. In our system, these optimum growth conditions are 100 mTorr background pressure with laser energy density 1.5–2 J/cm2. The sensitivity to growth conditions of the stoichiometry and structure of LaAlO3 films can have a crucial role in the 2-D electron gas formed at the LaAlO3/SrTiO3 interface.