Long Term Stability in Thin Film Ferroelectric Memories.
Abstract
The three main goals of the project have been accomplished: (1) a self-consistent model for the defect chemistry of Pb(Zr(1/2)Ti(1/2)O3 (PZT) was established, (2) the effect of doping on the degradation of the switchable remanent polarization ("fatigue") was determined, and (3) a field stage for the transmission electron microscope was designed and constructed so that dynamic domain switching can be observed and recorded on video tape. It was determined that the concentration of trapped holes exceeds that of free holes in PZT even at the temperatures of equilibration, and that the hole mobility is thermally-activated. It appears that electron-trapping is also extensive. The ac, bulk conductivity of quenched PZT is dominated by ionic conduction. The transport properties of PZT have been correlated with electron paramagnetic resonance results and theoretical band calculations done elsewhere. Polarization fatigue is enhanced by acceptor-doping, and suppressed by donor-doping in both thinned, bulk samples of BaTiO3 and PZT thin films. jg
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 15, 1995
- Accession Number
- ADA295504
Entities
People
- D. M. Smyth
- M. P. Harmer
Organizations
- Lehigh University