Growth mode control of the free carrier density in SrTiO3-δ films

We have studied the growth dynamics and electronic properties of SrTiO3-delta homoepitaxial films by pulsed laser deposition. We find that the two dominant factors determining the growth mode are the kinetics of surface crystallization and of oxidation. When matched, persistent two-dimensional layer-by-layer growth can be obtained for hundreds of unit cells. By tuning these kinetic factors, oxygen vacancies can be frozen in the film, allowing controlled, systematic doping across a metal-insulator transition. Metallic films can be grown, exhibiting Hall mobilities as high as 25 000 cm(2)/V s. (C) 2007 American Institute of Physics.