Lead Zirconate Titanate (PZT) thin films have been sputter deposited on p–Si. The patterned PZT films were annealed in a furnace as well as in a rapid thermal annealer. The high frequency characterization of metal–PZT– p– Si capacitors show good Capacitance–Voltage characteristics. The effective dielectric constant of PZT on Si was found to be very low and depends on the thickness of the PZT film and the annealing conditions. The high frequency C–V shows hysteresis which is due to the injection of charges across the interface.

The ferroelectric properties and switching characteristics of rf sputtered PZT thin films were investigated as a function of film thickness (30–300 nm) and grain size. Electron microscopy was used to characterize the film microstructure. The film thickness was measured by ellipsometer. The results were analyzed for the individual contributions of film thickness and crystallite dimension to the size effects on the properties of ferroelectric thin films. A critical discussion of several different models describing the size effects was also presented.

A new computational method for simulating the dynamics of switching in ferroelectric materials is presented. The new method is shown to be more realistic for dynamic simulations and computationally more efficient than the traditional Monte Carlo method. The method is used to investigate the effect of polar defects on switching behavior. The results are in qualitative agreement with experimental observations of fatigue.

This paper investigates the issues in the scaling of thin film PZT (Lead-Zirconate-Titanate) capacitors for DRAM (Dynamic Random Access Memories) applications. The test structures used were MIM (metal-insulator-metal) capacitors with platinum electrodes and PZT deposited using a sol-gel process. Charge storage density (Q'c), leakage current density (JL), unipolar switching time to 10% decay (ts), time dependent dielectric breakdown (TDDB) and electrical fatigue have been analyzed. Unipolar switching time has been modeled as an RC time constant, where C is electric-field dependent. Q'c at a given electric field appears to remain constant over the range of film thicknesses and electrode areas studied. Leakage current density and time-to-breakdown (tBD) for a given electric field degrade with decreasing film thickness. Unipolar stressing causes considerably less fatigue than bipolar stressing, and after 2 × 1011 cycles, a 400nm film still exhibits sufficient Q'c for DRAM operation.