PREPARATION OF (PB0.88LA0.12)TIO3 THIN-FILMS FOR DYNAMIC RANDOM-ACCESS MEMORY BY LOW PRESSURE-METALORGANIC CHEMICAL-VAPOR-DEPOSITION

Abstract

La-modified lead titanate (PLT) thin films were prepared by hot-wall type low pressure-metalorganic chemical vapor deposition method. Pb(dpm)(2), La(dpm)(3), and titanium tetraisopropoxide were used as source materials. The films were deposited at 500 degrees C under the low pressure of 1000 mTorr and then annealed at 650 degrees C for 10 min in oxygen ambient. Sputter-deposited platinum electrodes and 180 nm thick PLT thin films were employed to form MIM capacitors with the best combination of high charge storage density (26.7 mu C/cm(2) at 3V) and low leakage current density (1.5 x 10(-7) A/cm(2) at 3V). The measured dielectric constant and dielectric loss were 1000 similar to 1200 and 0.06 similar to 0.07 at zero bias and 100 kHz, respectively.