Investigation of factors affecting electrical properties of PZT thin film capacitors

Effects of morphology of Pt, orientation of PZT, and stoichiometry of PZT on electrical properties of PZT thin film capacitors prepared using the sol-gel technique were investigated. Although the predominant orientation of PZT grown on as-deposited Ti/Pt was (100), both heat-treatment of Ti/Pt bottom electrode and application of the Ti-seed technique to Ti/Pt bottom electrode promoted (111) orientation of PZT. However, the surface of PZT on heat-treated Ti/Pt was very rough in contrast to the smooth surface for Ti-seeded PZT. Remnant polarization P/sub r/ increased from 14 [/spl mu/C/cm/sup 2/] for (100) orientation of PZT formed on as-deposited Ti/Pt to 31 [/spl mu/C/cm/sup 2/] for heat-treatment and 44 [/spl mu/C/cm/sup 2/] for Ti-seed. However, fatigue properties did not improve even though surface morphology of Ti/Pt bottom electrode and orientation of PZT were changed. Electrical properties of PZT showed strong stoichiometry (A/B) dependence of PZT. In particular, excess PbO by 30 mole % (A/B=1.30) revealed great fatigue performance.