Deposition and Electrical Characterization of Very Thin SrTiO₃ Films for Ultra Large Scale Integrated Dynamic Random Access Memory Application

Abstract

SrTiO 3 thin films are deposited on Pt/SiO 2 /Si substrates using RF magnetron sputtering in a temperature range from 200° C to 600° C. The film deposited at 600° C shows the best dielectric property and leakage current characteristics due to its good crystallinity and stoichiometric composition. Dielectric constant of the film deposited at 600° C decreases with decreasing thickness from 235 at 120 nm to 145 at 30 nm. Leakage current shows a constant value of about 30 nA/cm 2 at 1.6 V in a thickness range from 50 nm to 120 nm but increases rapidly to 5 µ A/cm 2 at 30 nm. The electrical properties of the films are explained by a model of the Pt/SrTiO 3 /Pt capacitor based on the band structure.