Search for new high-κ dielectrics by combinatorial chemical vapor deposition

To develop a high-κ gate dielectric for replacing SiO₂ in MOSFETs, multi-component metal oxides could have advantages over single metal oxides because they may offer higher dielectric constants (κ's) as well as other favorable properties. To find the film composition for obtaining a good dielectric from the given component oxides is a time-consuming and costly process for multi-component systems. Recently, we reported a combinatorial chemical vapor deposition (CVD) technique to deposit compositional spreads of ternary metal-oxides for high-κ dielectrics. In this work, compositional spreads of ZrO₂, TiO₂, SnO₂ and HfO₂ were deposited using anhydrous metal nitrates. By measuring chemical composition, film thickness, and electrical properties, we are able to map κ and establish its dependence on film composition. This high-throughput deposition technique allows us to generate a compositional library quickly for screening material properties. In addition, a crystalline phase which does not exist in any of the four pure oxides, α-PbO₂, was detected.