화학공학소재연구정보센터
Journal of the Electrochemical Society, Vol.158, No.6, G137-G140, 2011
Forming Gas Annealing Induced Degradation in Nanoscale Electrical Homogeneity of Bismuth Ferrite Thin Films
In this study, 60 nm-thick BiFeO3(BFO) thin films with (h00) orientation were successfully grown on LaNiO3(LNO)-buffered Pt/Ti/SiO2/Si(100) substrates. The effects of the temperature (300-500 degrees C) of forming gas (7% H-2 + 93% Ar) annealing (FGA) on the physical properties of the BFO thin films were investigated. The x-ray diffraction results show that the higher FGA temperature results in a larger degree of deterioration in crystal quality of the BFO thin films. This change can be attributed to a loss of oxygen from the BFO thin films and the incorporation of hydrogen atoms into the lattice of the film during FGA. FGA produces an increase in surface roughness for the BFO thin films. The current maps obtained by conductive atomic force microscopy demonstrate that the leakage behaviors of BFO thin films, with and without FGA, at various temperatures under the breakdown electric field, are different. The leakage currents are detected mostly in areas surrounding large crystallites in BFO thin films with or without FGA at 300 degrees C. In contrast, large crystallites in the BFO thin films with FGA at 400-500 degrees C are electrically leaky and the detected currents are high compared to those of BFO thin films with and without FGA at 300 degrees C. (C) 2011 The Electrochemical Society. [DOI: 10.1149/1.3570960] All rights reserved.