SrTiO3 based side gate field effect transistor realized by submicron scale AFM induced local chemical reactions

In this work we will show how it is possible to apply the so called nano-oxidation technique to pattern electrical circuits on oxygen deficient SrTiO3 (STO) thin films. We will focus on two aspects: the chemical reactions which are triggered at the surface of oxygen deficient STO thin films by the voltage biased tip of an atomic force microscope (AFM) and the exploitation of this phenomenology to pattern insulating regions on oxygen deficient STO thin films in the submicron regime. Due to the insulating nature of the AFM modified regions and to the possibility to remove selectively the modified parts, planar electrical circuits entirely designed over STO thin films can be fabricated. A prototype of planar side gate field effect thin film transistor in which STO acts both as active channel and as gate electrode is presented and discussed.