Annealing characteristics of pulsed laser deposited homoepitaxial SrTiO3 thin films

The homoepitaxial growth of SrTiO3 (STO) films on as-polished STO(1 0 0) substrates by pulsed laser deposition has been exploited in detail. The intimate correlation between the surface step edge density and reflection high-energy electron diffraction (RHEED) intensity is clearly demonstrated by measuring the relation between the initial RHEED intensity drop and laser repetition rates. Systematic in situ annealing schemes were performed to investigate the film growth mechanisms. The results indicate that the two or three level growth may have occurred during some annealing schemes and can be interpreted by Stoyanovʹs step edge density model. Complementary atomic force microscopy investigations of the film surfaces further lend direct support to the RHEED intensity observations.