Abstract:
Ferroelectric thin films such as BST, PZT and PLZT are extensively being studied for the fabrication of
DRAMS since they have high dielectric constant. The large and reversible remnant polarization of these
materials makes it attractive for nonvolatile ferroelectric RAM application. In this paper we report the
characterization of Ba0.7Sr0.3TiO3 (BST) thin films grown by pulsed laser ablation on oxide electrodes.
The structural and electrical properties of the fabricated devices were studied. Growth of crystalline BST
films was observed on La0.5Sr0.5CoO3 (LSCO) thin film electrodes at relatively low substrate temperature
compared to BST grown on PtSi substrates. Electrical characterization was carried out by fabricating
PtSi/ LSCO/ BST/ LSCO heterostructures. The leakage current of the heterostructure is studied and a band
structure is modeled based on the transport properties of the heterostructure. The dielectric constant
of the BST film is found to be 630 at 100 kHz with a loss tangent of 0.04. The capacitance voltage
characteristics show high tunability for BST thin films.
