Solution processing of Pt and La_0.5Sr_0.5CoO₃ electrodes for ferroelectric memories

Abstract

The processing of Pt and La_0.5Sr_0.5CoO₃ electrodes for integrated ferroelectrics by metallo-organic (MOD) decomposition is described. Hillock-free platinum films can be obtained by this method. However, for integration of lead zirconium titanate, lead diffusion through the MOD Pt layer has been severe for certain PZT compositions. In order to minimize diffusion, a barrier layer is required. La_0.5Sr_0.5CoO₃ electrodes have also been prepared on SiO₂/Si substrates. The MOD-prepared lanthanum strontium cobalt oxide layer appeared to react with Si to produce a layer which was preferentially etched during solution processing. In order to overcome the problems associated with the individual layers, we have prepared hybrid electrode structures of Pt/La_0.5Sr_0.5CoO₃ or La_0.5Sr_0.5CoO₃/Pt. The combined electrode gave improved ferroelectric properties for PZT capacitors.

Keywords:

• Metallo-organic decomposition
• platinum
• La_0.5Sr_0.5CoO₃
• PZT
• electrodes
• ferroelectric memories