Ultra High-k HfZrO4 Thin Films Grown by Atomic Layer Deposition using Metal-Organic and Brute HOOH precursors

Lower leakage at low EOT is a requirement for DRAM application. High-k materials such as TiO
2
have shown low EOT (3.5A-4A) but suffer from small band gap and high leakage
¹
. Ferroelectric/antiferroelectric HfZrO
4
films have shown high-k at 10nm but as the films are scaled, the dielectric properties of the films decrease
^{2, 3}
. The key to low EOT is to find a material with high-k at 5 nm or sub-5nm thickness with low leakage. In the present study, HfZrO
4
films were fabricated with HOOH and metal organic precursors which demonstrate very high-k (∼88) at 5 nm thickness with TiN and W electrodes in metal-insulator-metal (MIM) device structure.