Comparison of Epitaxial and Textured Ferroelectric BaTiO&lt;sub&gt;3&lt;/sub&gt; Thin Films

Baba Wague,Pedro Rojo Romeo,Yves Robach,Bertrand Vilquin,Nicolas Baboux

doi:10.4236/jmp.2020.114033

Abstract

The properties of BaTiO3 (BTO) thin films deposited on different substrates by RF magnetron sputtering were investigated. Two representative substrates were selected and different heterostructures were studied. 1) SrTiO3 (STO) single crystals as a bulk oxide reference material, and 2) silicon as a semiconductor. SrRuO3 (SRO) and Pt bottom electrodes were deposited on the silicon substrate. The BTO structural characterizations show that all the films have (001) crystallographic orientation. We have compared the electrical properties of the different samples: the same dielectric constant and polarization values were obtained independently of the nature of the substrate.

Highlights

Among the ferroelectric perovskites, BaTiO3 (BTO) has intensively been studied for a wide range of applications [1], MEMS devices [2], non-volatile memories, electro-optical devices [3], and piezoelectric and electro-optical properties [4]
We investigate the structural and dielectric properties of 300 nm thick BTO thin films deposited by RF sputtering on different stacks of electrode/substrate: 1) SrRuO3/SrTiO3, 2) Pt/TiO2/SiO2/Si and 3) SrRuO3/SrTiO3/Si
The BTO thin films on all substrates were prepared by RF magnetron sputtering from a stoichiometric BaTiO3 ceramic target

Summary

Introduction

BaTiO3 (BTO) has intensively been studied for a wide range of applications [1], MEMS devices [2], non-volatile memories, electro-optical devices [3], and piezoelectric and electro-optical properties [4]. The fact that its composition is lead-free makes BTO very interesting for applications and many papers have discussed electrical and structural properties of BTO thin films [5] [6]. High quality BTO thin films have generally been grown on lattice matched substrate such as MgO and SrTiO3 (STO). STO single-crystal is used as substrate as it has a perovskite structure and its lattice parameters are close to those of BTO [16]. The substrate and the bottom contact layer have to ensure good quality growth, and sufficient mechanical and thermal stabilities. We investigate the structural and dielectric properties of 300 nm thick BTO thin films deposited by RF sputtering on different stacks of electrode/substrate: 1) SrRuO3/SrTiO3, 2) Pt/TiO2/SiO2/Si and 3) SrRuO3/SrTiO3/Si

Experimental Procedure

Results and Discussion

Conclusion