Structural and ferroelectric properties of (Bi,Ce)_4Ti_3O_(12) thin films grown by pulsed laser deposition for ferroelectric random access memories

摘要

The (Bi_(3.25)Ce_(0.75))Ti_3O_(12) (BCT) thin films with Bi-excess composition were prepared onto Pt/TiO_2/SiO_2/Si substrates at various temperatures using pulsed laser deposition (PLD) and annealed at various temperatures. The 20 mol% Bi-excess BCT films deposited at 400 ℃ showed a pure layered structure, the lowest root mean square (rms) roughness, and good ferroelectric properties after annealing at 700 ℃ in an oxygen ambient. The 70 nm thick-BCT films annealed at 800 ℃ for 10 min in O_2 showed well-saturated P-E-curves at an applied electric field of 3 V and a 2P_r of 23 μC/cm~2 and a E_c of 180 kV/cm at 5 V. The polarization values were not significantly changed after being subjected to 1.0 x 10~(10) switching cycles.