Structural and ferroelectric properties of (Bi,Ce)4Ti3O12 thin films grown by pulsed laser deposition for ferroelectric random access memories

The (Bi3.25Ce0.75)Ti3O12 (BCT) thin films with Bi-excess composition were prepared onto Pt/TiO2/SiO2/Si substrates at various temperatures using pulsed laser deposition (PLD) and annealed at various temperatures. The 20mol% Bi-excess BCT films deposited at 400°C showed a pure layered structure, the lowest root mean square (rms) roughness, and good ferroelectric properties after annealing at 700°C in an oxygen ambient. The 70nm thick-BCT films annealed at 800°C for 10min in O2 showed well-saturated P–E curves at an applied electric field of 3V and a 2Pr of 23μC/cm2 and a Ec of 180kV/cm at 5V. The polarization values were not significantly changed after being subjected to 1.0×1010 switching cycles.