Atomic-scale study of dead layers in epitaxial perovskite dielectric thin films with oxide and metal top electrodes
- Journal
- Advanced Electronic Materials (Adv. Electr. Mat.)
- Date
- 2024.02.25
- Abstract
Perovskite-oxide-based capacitors, which exhibit high charge storage capacity, have attracted considerable attention as a potential candidate for overcoming the limitations of nanoscale integration. To this end, a dead layer, which degrades the charge storage capacity at the interface between the electrode and the dielectric, has been extensively investigated. The dead layer in perovskite-oxide-based capacitors exhibits different characteristics depending on the electrode materials; however, a method for minimizing the dead layer is lacking. In this study, the charge storage capacity of a perovskite-oxide-based capacitor was evaluated considering the effect of the Ru and SrRuO3 top electrodes on the SrRuO3/Ba0.5Sr0.5TiO3 stack. Dead layers at the interface between each top electrode material and the dielectric were studied on an atomic scale; the results indicate that the Ru metal electrode causes oxygen diffusion from the dielectric to the electrode, forming elongated perovskite oxide at the interface, which acts as a dead layer. We determined the enhanced dielectric permittivity (from 667 to 953) by minimizing the dead layer at the top interface. Consequently, we intuitively identified the phenomenon and mechanism of the dead layer. This study proposes a method to overcome the limitations of the next-generation DRAM.
- Reference
- Adv. Electron. Mater. 2024, 10, 2300773
- DOI
- https://doi.org/10.1002/aelm.202300773