Degradation-free dielectric property using bismuth layer-structured dielectrics having natural superlattice structure

Abstract

Degradation -free dielectric property was obtained by using films of bismuth layer-structured dielectrics (BLSDs) having a natural superlattice structure. Investigation of the effects of the stack direction of the bismuth oxide and pseudoperovskite layers on the dielectric properties of c-axis-oriented epitaxial BLSD films revealed that those with an even number of octahedra in the pseudoperovskite layer did not show significant degradation in the dielectric constant and retained good insulating characteristics when the film thickness was decreased despite the increased strain applied to the film. This was found not only in epitaxially grown films but also in one-axis-oriented ones with in-plane random orientation. In addition, films with a-/b-axis-oriented epitaxial BLSDs can be used a mold with a periodic nano-structure.