We have developed a new combinatorial technique, "carrousel deposition" for the atomically controlled growth of oxide films under in situ diagnostics of surface reaction with reflection high energy electron diffraction (RHEED). In this technique, a sequential fabrication of eight different films is performed in one experiment, enabling quick optimization of the growth conditions with the assistance of RHEED monitoring. Thus, we succeeded in the one lot optimization of the layer-by-layer SrO and BaO film growth on the B-site (TiO2) terminated SrTiO3(0 0 1) substrate. Furthermore, the characteristic, crystal habit in the initial growth of MO atomic layers on the SrTiO3 substrate was elucidated to be dominated by the topmost atomic layer of the substrate or film and the atomic layer to be formed on it. (C) 2002 Elsevier Science B.V. All rights reserved.