Systematic investigation of the annealing temperature and composition effects on the dielectric properties of solgel BaxSr1-xTiO3 thin films

Delphin Levasseur (1) , Heba Badr El Din Badr El-Din El-Shaarawi (2) , Sébastien Pacchini (3) , Anthony Rousseau (1) , Sandrine Payan (1) , Guillaume Guegan (4) , Mario Maglione (1)

1 ICMCB - Institut de Chimie de la Matière Condensée de Bordeaux
2 LAAS - Laboratoire d'analyse et d'architecture des systèmes
3 LAAS-MINC - Équipe MIcro et Nanosystèmes pour les Communications sans fil
4 ST-AGRATE - STMicroelectronics [Agrate Brianza]

In this work, BaxSr1-xTiO3 solgel thin films (x=0.7, 0.5 and 0.3) deposited on Pt/Si substrate and post-annealed at different temperatures have been investigated. A systematic study of the structure, microstructure and of the dielectric properties have been achieved for each composition. To our knowledge, for the first time, a systematic effect of post-deposition annealing temperature and composition is reported. For each Ba/Sr ratio, higher annealing temperature leads to crystallinity improvement and to grain growth. A shift of the ferroelectric to paraelectric transition toward the bulk Curie temperature with the increase of the annealing temperature is shown. These results are correlated with the increase of the permittivity, tunability and dielectric losses measured on MIM capacitors at low frequency. Moreover, the high frequency results, between 800MHz and 30GHz, are in very good agreement with low frequency measurements, and show a huge tunability up to 80% under 600kV/cm.

Mots clés: Films; Grain size; Dielectric Properties; BaTiO3 and titanates; Capacitors

Domaines: Micro et nanotechnologies/Microélectronique

Delphin Levasseur, Heba Badr El Din Badr El-Din El-Shaarawi, Sébastien Pacchini, Anthony Rousseau, Sandrine Payan, et al.. Systematic investigation of the annealing temperature and composition effects on the dielectric properties of solgel BaxSr1-xTiO3 thin films. Journal of the European Ceramic Society, 2013, 33 (1), pp.139-146. ⟨10.1016/j.jeurceramsoc.2012.07.041⟩. ⟨hal-00797624⟩