Low equivalent oxide thickness metal/insulator/metal structures for DRAM application

We have prepared metal/insulator/metal (MIM) structures with RuO
2
bottom electrode and TiO
2
dielectric film for advanced dynamic random access memory (DRAM) technology. RuO
2
films were grown by metal organic chemical vapour deposition while TiO
2
films were prepared by atomic layer deposition. RuO
2
bottom electrode crystallizes in rutile structure and induces growth of rutile TiO
2
. Equivalent oxide thickness (EOT) as low as 0.39 nm and dielectric constant as high as 130 was obtained. It was found that leakage current strongly depends on either oxygen treatment after deposition or its admixture to the carrier gas during TiO
2
deposition. However, MIM structures under study show higher leakage current that is expected for the application (~10
^-7
A/cm
²
) in DRAM technology.