Preparation of Pb(Zr,Ti)O3 thin films by metalorganic chemical vapor deposition for low voltage ferroelectric memory

To realize the full potential of high density embedded ferroelectric memory, ferroelectric film thickness must be scaled below 100 nm to ensure that the capacitor. operating voltage is compatible with advanced, low voltage logic transistors. In this article, we describe recent progress in the preparation of sub-100 nm thick Pb(Zr,Ti)O-3 (PZT) thin films by metalorganic chemical vapor deposition an,200 mm wafers using an industry-standard processing platform. Within the full range of thicknesses investigated, 134-52 nm, capacitor operating voltage scales linearly with film, thickness, yielding 71 nm thick films with a switched polarization (P-sw) of similar to40 muC/cm(2) at 1.2 V. Below similar to50 nm, PZT surface roughness makes further thickness scaling difficult. With improved surface morphology, however, even lower operating voltages should be feasible. (C) 2003 American. Institute of Physics. [DOI: 10.1063/1.1534380].