Electrical characterization of SrTiO3 thin films grown on Nb-doped SrTiO3 single crystals

SrTiO3(100) films homoepitaxially grown on Nb-doped SrTiO3(100) substrates with various Nb concentrations and SrTiO3(111) films epitaxialy grown on th e [111]-oriented Pt thin-film electrode formed on SiO2/Si substrates with T a buffer layers were prepared by the helicon sputtering method. After the t op Pt electrode formation, the obtained Pt/SrTiO3/SrTiO3:Nb metal-insulator -semiconductor (MIS) capacitors and Pt/SrTiO3/Pt/Ta/SiO2/Si metal-insulator -metal (MIM) capacitors were electrically evaluated by current versus bias voltage characteristic (I-V) and capacitance versus bias voltage characteri stic (C-V) measurements to clarify the specific features of the SrTiO3/SrTi O3:Nb interface compared with the SrTiO3/Pt interface. The existence of a s pace charge layer at the SrTiO3/SrTiO3:Nb interface was clearly characteriz ed.