Nano-pattern formation on SrTiO3/Si(111) surface

Abstract

High dielectric materials are used extensively in electronic industry in the fabrication of random access memory (RAM) devices to increase the storage density. High dielectric materials are used as gate dielectric in the capacitor structures used to make RAMs. The strontium titanate (SrTiO3) is highly stable on Si surface even at high processing temperatures required for device fabrication. SrTiO3 is used also in actuators, oxygen sensors, photoelectrodes for splitting of water into hydrogen and oxygen. The oxygen defects introduced during the preparation process increase the oxygen sensing efficiency of SrTiO3. The well characterized SrTiO3/Si structures are under high demand to understand the role played by the structures in device functioning. High purity bulk SrTiO3 was prepared by solid state reaction method using 99.99% pure TiO2 and SrCO3 as starting materials. The SrTiO3 was deposited onto clean Si(111) surface by pulsed laser deposition technique and was investigated sing grazing x-ray diffraction (XRD) and Atomic Force Microscopy (AFM) techniques. Our grazing XRD results suggested the formation of crystalline SrTiO3 film on Si surface. The AFM studies indicated the well organizednano void pattern formation with an average size of about 26 nm. SrTiO3 film with such voids increases the oxygen sensing efficiency manifold.