The viability of lead zirconate titanate (PZT) films as a storage dielectric for DRAM applications is discussed. 4000 angstrom PZT films with an effective SiO2 thickness less than 17 angstrom were prepared by sol-gel deposition. The films exhibited ohmic behavior at low fields and exponential field dependence at high fields. The conduction characteristics can be modeled accurately using expressions derived for ionic conductivity. At the same effective SiO2 field, the leakage and time-dependent dielectric breakdown (TDDB) characteristics are superior to other dielectric structures. However, lifetime extrapolations to worst-case operating conditions show that TDDB may be a very serious limitation for DRAM applications. Optimization of material properties of PZT films, especially the TDDB lifetime, is necessary for reliable DRAM operation.
|Number of pages||6|
|Journal||Annual Proceedings - Reliability Physics (Symposium)|
|State||Published - 1 Dec 1990|
|Event||Twenty Eight International Reliability Physics Symposium 1990 - New Orleans, LA, USA|
Duration: 27 Mar 1990 → 29 Mar 1990