Growth and Microstructural Studies of Strontium Titanate Films Grown by Standard and Interval Pulsed Laser Deposition

Strontium titanate films were grown by standard and interval pulsed laser interval deposition on (001) strontium titanate and magnesium oxide substrates. Reflection high-energy electron diffraction (RHEED) was used to monitor the growth mode of the films. The microstructures were investigated using transmission electron microscopy. The temporal evolution of the RHEED intensity confirmed a layer-by-layer growth mode in the homoepitaxial case. In heteroepitaxy, three dimensional growth occurred. Misfit dislocations and threading dislocations were the dominant defects. The film grown using the standard deposition was relaxed; the film grown using interval deposition was under in-plane tension and showed fewer threading dislocations.