Prevention of degradation of (Ba,Sr)TiO[sub 3] during forming gas anneal by a SiO[sub 2] capped (Ba,Sr)RuO[sub 3] electrode.

Degradation of (Ba,Sr)TiO[sub 3] during a forming gas anneal was examined and the effect of a SiO[sub 2] capped (Ba,Sr)RuO[sub 3] electrode was studied. All the samples were prepared by a rf magnetron sputtering technique and the forming gas (10% H[sub 2]+90% N[sub 2]) anneal was carried out at 400 °C for 30 min. The (Ba,Sr)RuO[sub 3] film directly exposed to H[sub 2] ambient was damaged severely, which resulted in the reduction and phase separation into BaO and Ru. On the other hand, the SiO[sub 2] capped (Ba,Sr)RuO[sub 3] film was not damaged during H[sub 2] annealing. By adopting the SiO[sub 2] capped (Ba,Sr)RuO[sub 3] as an electrode of (Ba,Sr)TiO[sub 3], the degradation of (Ba,Sr)TiO[sub 3] could be inhibited. SiO[sub 2] capping also decreased the extent of the reduction of a Pt/(Ba,Sr)TiO[sub 3]/Pt structured capacitor, which is known to degrade dramatically. It is believed that the major cause of the tolerance to the forming gas anneal is the blocking capability of SiO[sub 2] against the diffusion of reaction products such as H[sub 2]O. © 2003 American Institute of Physics. [ABSTRACT FROM AUTHOR]