OXYGEN PLASMA EFFECTS ON ELECTRICAL-PROPERTIES OF BARIUM STRONTIUM-TITANATE (BST) THIN-FILMS

Abstract

(Ba0.5Sr0.5)TiO3 thin films have been prepared on Pt/Ta/SiO2/Si substrates by means of a conventional rf magnetron sputtering method with ceramic target and excess BaO, SrO target under various Ar/O-2 plasma conditions. Electric properties of the films have been studied. Increase of O-2 plasma content improve dielectric and insulating properties of the films. An 80nm-BST thin film deposited with 50% O-2 plasma content has a dielectric constant of 446 and a leakage current density of 1.5x10(-7)A/cm(2) at 3V. In the current-voltage curve of BST film deposited with higher O-2 plasma content, a wider saturated region of hopping conduction appeares.