Cs. Hwang et al., DEPOSITION AND ELECTRICAL CHARACTERIZATION OF VERY THIN SRTIO3 FILMS FOR ULTRA LARGE-SCALE INTEGRATED DYNAMIC RANDOM-ACCESS MEMORY APPLICATION, JPN J A P 1, 34(9B), 1995, pp. 5178-5183
SrTiO3 thin films are deposited on Pt/SiO2/Si substrates using RF magn
etron sputtering in a temperature range from 200 degrees C to 600 degr
ees C. The film deposited at 600 degrees C shows the best dielectric p
roperty and leakage current characteristics due to its good crystallin
ity and stoichiometric composition. Dielectric constant of the film de
posited 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 a
bout 30 nA/cm(2) at 1.6 V in a thickness range from 50 nm to 120 nm bu
t increases rapidly to 5 mu A/cm(2) at 30 nm. The electrical propertie
s of the films are explained by a model of thr Pt/SrTiO3/Pt capacitor
based on the band structure.