Fabrication and Properties of Metal-PZT-Metal Capacitors by Liquid Delivery MOCVD

摘要

Pb(Zr_(1-x),Ti_x)O_3(PZT) thin films were prepared on 8-inch and 4-inch Pt or Ir-electroded Si wafers by liquid delivery metal-organic chemical vapor deposition (LD-MOCVD) using cocktail sources of Pb, Zr and Ti. The processing conditions were optimized in order to obtain high-performance PZT films. The thickness uniformity of PZT films on 8-inch substrate was about ±3.24%. The deposition rate of Pb (15.8 nm/min) and Ti (17.9 nm/min) deposited on Si substrate were faster than that of Zr (2.5 nm/min). The growth temperature of PZT film was adjusted to 570-630 deg C depending on the substrates used. The properties of metal/PZT/metal capacitors were also studied. The PZT films based on Pt substrate showed no good ferroelectric properties. By contrast, the ferroelectric properties of Ir/IrO_2/PZT/IrO_2/Ir capacitors were excellent. At an applied voltage of 5 V, the remanent polarization (P_r) and coercive field (E_c) values were about 36 mu C/cm2 and 50 kV/cm, respectively.