Structure and electrical properties of sputter deposited (Ba1-x,Sr-x) (Ti1-y,Zr-y)O-3 thin films

(Ba1-x,Sr-x)(Ti1-y,Zr-y)O-3 thin films as the dielectric materials for giga bit-scale dynamic random access memory was deposited by radio frequency mag netron sputtering. The films with controlled compositions were grown from a single target by the control of chamber pressure. When chamber pressure de creased, the dielectric constant of films decreased due to an increase of Z r content. The (Ba1-x, Sr-x) (Ti1-y,Zr-y)O-3 thin films prepared in this st udy show a dielectric constant of 380 similar to 525 at 100 kHz. The films showed the decrease of leakage current as chamber pressure decreased and th e leakage current density of films deposited above 10 mTorr was 10(-7) simi lar to 10(-8) A/cm(2) at 200 kV/cm. The dominant transport mechanism of fil ms was the interface limited Schottky emission conduction. The (Ba1-xSrx)(T i1-y,Zr-y)O-3 thin film appeared to be potential dielectric material for hi gh density dynamic random access memory. (C) 2001 The Electrochemical Socie ty.