Significant suppression of leakage current in (Ba,Sr)TiO3 thin films by Ni or Mn doping

Abstract

Effects of Ni or Mn doping in (Ba0.5Sr0.5)TiO3 thin films on leakage current behaviors of Pt/(Ba0.5Sr0.5)TiO3/Pt capacitors were investigated. The leakage current level was found to reduce significantly after the doping over a wide range of voltages and temperatures. The leakage current in an undoped capacitor was largely governed by the Fowler-Nordheim tunneling, and its onset voltage was greatly increased in doped capacitors. The suppression of leakage current in doped capacitors appeared to be caused by a widened depletion layer, which decreases the likelihood of tunneling. (C) 2002 American Institute of Physics.