CHANGES IN THE CRYSTAL-STRUCTURE OF RF-MAGNETRON SPUTTERED BATIO3 THIN-FILMS

The crystal structure of BaTiO3 thin films fabricated by RF-magnetron sputtering has been investigated. As-sputtered films exhibited a cubic structure with a small grain size of about 6-8nm. After annealing at a temperature above 1100-degrees-C, the crystal structure changed from cubic to tetragonal, because the annealing process caused grain growth. The critical grain size of the thin films which provided the cubic structure existed in the range of 0.1-0.2-mu-m. This value agreed well with the critical grain size of BaTiO3 fine particles, 0.12-mu-m.