Effects of post oxygen plasma treatment on Pt/(Ba,Sr)TiO/sub 3//Pt capacitors at low substrate temperatures

This work investigated how oxygen plasma post-treatment improves the leakage characteristics of Pt/(Ba,Sr)TiO/sub 3/(BST)/Pt capacitors prepared by the RF cosputtering technique. Experimental results indicate that oxygen plasma treatment can effectively passivate the oxygen vacancies of BST films, thus decreasing the electric conduction paths of leakage currents. Via this low-temperature (250 /spl deg/C) and short duration (/spl sim/5min) process, the leakage current is reduced by as many as two orders of magnitude. Excellent electrical characteristics, including low leakage current (1.5/spl times/10/sup -8/ A/cm/sup 2/) under 0.1 MV/cm, high dielectric constant (288), and greater than 10 year lifetime under 2 MV/cm can be achieved.