DEPOSITION AND ELECTRICAL CHARACTERIZATION OF VERY THIN SRTIO3 FILMS FOR ULTRA LARGE-SCALE INTEGRATED DYNAMIC RANDOM-ACCESS MEMORY APPLICATION

Abstract

SrTiO3 thin films are deposited on Pt/SiO2/Si substrates using RF magnetron sputtering in a temperature range from 200 degrees C to 600 degrees C. The film deposited at 600 degrees 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 degrees 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 mu A/cm(2) at 30 nm. The electrical properties of the films are explained by a model of thr Pt/SrTiO3/Pt capacitor based on the band structure.