Title :
Effect of bottom electrode of ReRAM with Ta2O5/TiO2 stack on RTN and retention
Author :
Terai, M. ; Sakotsubo, Y. ; Saito, Y. ; Kotsuji, S. ; Hada, H.
Author_Institution :
Device Platforms Res. Labs., NEC Corp., Sagamihara, Japan
Abstract :
The Effect of the bottom electrode of ReRAM with a Ta2O5/TiO2 stack on noise and retention was investigated. The current fluctuation due to complex random telegraph noise (RTN) resulted in errors in the read-out with multi-level operation. We clarified that the Ti diffusion into the TiO2 layer from the bottom electrode increased the trap density and thus degraded current stability. The increased density caused the minority bit in the reset state to fail under a high temperature stress. The use of a stack with a Ru or Pt electrode with controlled Ti diffusion resulted in low noise and high thermal stability (>190°C).
Keywords :
integrated circuit noise; platinum; random-access storage; ruthenium; tantalum compounds; thermal stability; titanium compounds; RTN; ReRAM; Ta2O5-TiO2-Pt; Ta2O5-TiO2-Ru; bottom electrode; current fluctuation; degraded current stability; high temperature stress; high thermal stability; low noise; multi-level operation; random telegraph noise; retention; trap density; Acoustic waves; Elasticity; Electrodes; Frequency measurement; Manufacturing; Mirrors; Piezoelectric materials; Stress; Temperature distribution; Tungsten;
Conference_Titel :
Electron Devices Meeting (IEDM), 2009 IEEE International
Conference_Location :
Baltimore, MD
Print_ISBN :
978-1-4244-5639-0
Electronic_ISBN :
978-1-4244-5640-6
DOI :
10.1109/IEDM.2009.5424226
