Growth mode mapping of SrTiO3 epitaxy

Abstract

We have mapped the growth mode of homoepitaxial ${\mathrm{SrTiO}}_{\mathrm{3}}$ thin films as a function of deposition rate and substrate temperature during pulsed laser deposition. The transition from layer by layer growth to step flow growth was mapped by making 260 depositions, 3 monolayers each, on a single substrate. The growth mode was determined by time-resolved reflection high-energy electron diffraction. An atomically smooth surface was regenerated after each deposition by annealing the sample at temperatures above $\text{1200\hspace{0.05em}°}\mathrm{C}.$ The depositions were performed at an oxygen pressure of ${10}^{\text{−6}} \mathrm{Torr}$ and covered a temperature range from 900 to $\text{1380\hspace{0.05em}°}\mathrm{C}.$ The effective activation energies of surface migration on Ti- and Sr-terminated surfaces were determined from the mapping results.