Characteristics of zirconium based amorphous thin films deposited by Co-sputtering

In this study, we investigate effects of compositional ratios of zirconium based amorphous films for alternative gate dielectric applications. To obtain amorphous films, Si and Bi as glass former materials are evaluated. The dielectric constant of Zr based films is directly related to the Zr concentration. So, higher Zr concentration results in higher dielectric constant. However, high glass forming material concentration is preferred to obtain good thermal stability. Amorphous thin films were deposited by reactive co-sputtering because of its easiness on compositional change. However, reactive sputtering easily causes undesirable interfacial layers. In order to reduce the interfacial layers, amorphous films is formed by oxidation method. Especially, the amorphous films of Zr_xBi_1-xOy X = 0.45 prepared by oxidation shows CET of 17Å and leakage current density of 1×10 ^-3 A/cm² at - 1.0V.