Effect of low pressure dc plasma discharge on laser ablated ferroelectric Pb(Zr,Ti)O₃ thin films

Abstract

Ferroelectric thin films of PZT [Pb(Zr,Ti)O₃] were deposited on platinum coated silicon and bare silicon by excimer laser (248 nm) ablation and were in situ crystallized, with and without an oxygen discharge. Films deposited at various oxygen discharge voltages exhibited variations in polarization switching, dielectric constant, and loss, and current-voltage (I-V) characteristics. Crystalline perovskite PZT films deposited with a discharge voltage of +300 V offered stoichiometric and crystalline films, with a dielectric constant of 850, a remnant polarization of 22 µ C/cm², and a coercive field of 40 kV/cm, a resistivity of about 10¹² Ωcm and a charge storage density of as high as 100 fC/µ m2 at 5 V. Besides the property enhancement, the presence of O₂⁺ discharge plasma appeared to have reduced the deposition temperature to relatively lower values (500° C).