Deuterium annealing effects on the electrical properties of (Ba,Sr)TiO3 thin films were investigated by using electrical measurements and X-ray photo-electron spectroscopy band bending analysis as a function of Pt surface coverage. In combination with the results from secondary ion mass spectroscopy depth profiling, these results suggested that the majority of D defects incorporated during low temperature D2/N2 anneals was electrically inactive. Therefore, there were quite likely other contributors, in addition to charged interstitial D defects, to the observed leakage current degradation after D/H forming gas annealing, such as O vacancies formed under reducing D2 annealing conditions and annealing-induced changes in the (Ba,Sr)TiO3/Pt interface state density. The X-ray photo-electron spectroscopic band bending analysis provided information on the electrostatic potential difference across (Ba,Sr)TiO3 thin films with a Pt bottom electrode. With this boundary condition as input, simulations based upon a previously developed equilibrium point defect model and the static (annealing time independent) D depth profiles obtained by secondary ion mass spectroscopic analysis were performed to predict equilibrium defect distributions across BST thin films.

Point Defect Distributions and their Electrical Effects on (Ba,Sr)TiO3/Pt Thin Films. R.V.Wang, P.C.McIntyre: Journal of Applied Physics, 2003, 94[3], 1926-33