Thermal stability of platinum bottom electrode for bismuth titanate thin films

Platinum (Pt) films were widely used as an electrode in device applications of ferroelectric thin films. However, the surface morphology and microstructure were deformed during ferroelectric layer preparation. In this study, consequently, thermal stability of Pt bottom electrode for ferroelectric bismuth titanate (Bi 4 Ti 3 O 12 ) thin film fabrication was investigated. The deposited Pt film with thick Ti adhesion layer exhibits the different aspect areas, which contain Ti and/or Si element diffused into Pt grain boundaries. Therefore, the adhesion layer thickness was thinned as much as possible. Compressive stress was relaxed by hillock formation in plastic deformation region. Therefore, It is important to maintain the tensile stress from the substrate during the ferroelectric thin film formation. Bi 4 Ti 3 O 12 thin films deposited on stabilized Pt bottom electrode, exhibit superior dielectric properties. The deposited film exhibited ferroelectric properties. The polarization value at zero field of the strongly c-axis oriented one was 1.75 C/cm 2 . We think that the choke of silicon and/or titanium elements, diffused into Pt electrode, were effective against suppress hillock formation.