Submicrometric SrTiO3-d based devices realized by an atomic force microscope

SrTiO3 (STO) is one of the key compounds in the emerging field of oxide electronics. Because of the low carrier concentration needed to turn it into the conducting state (1018 e/cm3) and to its high bulk mobility (104 cm2/Vs @ 4.2 K), we consider STO suitable as functional conducting element in future oxide based devices. In this work we show how by applying a negative voltage to the conducting tip of an atomic force microscope it is possible to modify on sub-micron scale structural and electrical properties of conducting SrTiO3-? thin films grown on insulating LaAlO3 substrates, thus realizing sub-micrometric STO electrical circuits. After discussing the mechanisms of the process, we present the fabrication of a SrTiO3-? based side gate field effect transistor.