Pt/Pb(Zr, Ti)O3/Pt capacitor with excellent fatigue properties prepared by sol–gel process applied to FeRAM

Lead zirconate titanate (PZT) film is prepared on Pt/Ti/SiO2/Si substrate by proposed processes based on the sol–gel method and rapid thermal anneal (RTA). The ratio of Zr/Ti in the PZT film is 40/60. The PZT film has a mixture of perovskite orientations in which the (110) orientation is dominant. The Pt/PZT/Pt capacitor has remanent polarization of approximately 28.8 µC cm−2 and coercive voltage of approximately 0.76 V at 3 V voltage amplitude. The Pt/PZT/Pt capacitor has excellent fatigue properties. Switch polarizations decrease to 93.1% after 6 × 1012 switch cycles. The excellent fatigue properties result from the ameliorations of PZT/Pt interface conditions, restraining Pb volatilization and the directions of crystal domains in the RTA process. Some electric properties of the PZT capacitor proposed are contrasted with those of PZT capacitors with a different anneal process in the preparation.

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