The (Ba,Sr)RuO3 oxide electrode, which could enhance the electrical properties of (Ba,Sr)TiO3 dielectric films due to structural and chemical matches with (Ba,Sr)TiO3, was evaluated as an O diffusion barrier. It was possible to restrain the oxidation of TiN layer under BSR to TiO2 by the sequential deposition of amorphous (Ba,Sr)RuO3 and crystalline (Ba,Sr)RuO3; in which the amorphous (Ba,Sr)RuO3 eventually crystallized into crystalline (Ba,Sr)RuO3 during the deposition of crystalline (Ba,Sr)RuO3. When 2-step (Ba,Sr)RuO3 layers on TiN were annealed in an O ambient at 700C, the O atoms diffused and oxidized the TiN layer to TiO2. On the other hand, O could be effectively blocked by the (Ba,Sr)RuO3/Ru bilayer. In this system, the Ru sub-layer played a role as an O getter and the bilayer tended to block O diffusion. The blocking effect was more obvious when the thickness of (Ba,Sr)RuO3 in the bilayer was increased.

Evaluation of the (Ba,Sr)RuO3 and (Ba,Sr)RuO3/Ru Bilayer as an Oxygen Diffusion Barrier. J.H.Park, D.H.Hong, Y.B.Kim, D.K.Choi: Journal of Applied Physics, 2002, 91[12], 10022-7