Improvement of process stability for PZT thin films formation by using modified SOL-GEL solutions

Abstract

Pb(Zr, Ti)O₃ (PZT) thin films were prepared from conventional and modified sol-gel solutions with various Pb contents on Pt/SiO₂/Si substrate and evaluated. Comparing relationships between surface morphology of the PZT films derived from the solutions and Pb content in the solutions, same tendency that nano-crystalline secondary phase began to generate on surface of PZT films when the Pb content decreased was observed. However, the modified solutions had much wider window to produce PZT perovskite films without the secondary phase, namely good electrical properties. This was because nucleation density in PZT gel films was different between two solutions. The origin of the difference was discussed. For mass production of high density FeRAM, the control of the microstructure is key to stabilize the properties. By using modified sol-gel solutions, process stability for PZT films preparation was improved.

Key Words:

• PZT
• sol-gel
• microstructure
• nucleation
• Pb-content