Dielectric properties of amorphous Bi–Ti–O thin films

Abstract

We report the unexpectedly excellent dielectric properties of amorphous thin films with compositions in the Bi–Ti–O system. Films were deposited by RF magnetron reactive co-sputtering. In the composition range of 0.5 < x < 0.7, amorphous Bi1−xTixOy exhibits excellent dielectric properties, with a high dielectric constant, 𝜀r ∼ 53, and a dissipation factor as low as tan δ = 0.007. The corresponding maximum breakdown field reaches ∼1.6 MV/cm, yielding a maximum stored charge per unit area of up to 8 μC/cm2. This work demonstrates the potential of amorphous Bi–Ti–O as a high-performance thin-film dielectric material that is compatible with high-performance integrated circuits.

Keywords

• bismuth titanate
• amorphous
• thin films
• composition spread
• co-sputtering