Title :
Microscopic understanding of the low resistance state retention in HfO2 and HfAlO based RRAM
Author :
Traore, B. ; Blaise, P. ; Vianello, E. ; Grampeix, H. ; Bonnevialle, A. ; Jalaguier, E. ; Molas, G. ; Jeannot, S. ; Perniola, L. ; DeSalvo, B. ; Nishi, Y.
Author_Institution :
LETI, CEA, Grenoble, France
Abstract :
We study in detail the impact of alloying HfO2 with Al (Hf1-xAl2xO2+x) on the device characteristics through materials characterization, electrical measurements and atomistic simulation. Indeed, movements of individual oxygen atoms inside the dielectric are at the heart of RRAM operations. Therefore, we performed diffusion barrier calculations relative to the oxygen vacancy (VO) movement involved in Ron data retention. Calculations are performed at the best level using ab initio techniques. Our study provides an insight on the improved Ron stability of Hf1-xAl2xO2+x RRAM, via a simple explanation based on its higher atomic density (atoms/cm3) associated with shorter bond lengths between cations and anions in the presence of Al.
Keywords :
ab initio calculations; alloying; diffusion barriers; hafnium compounds; resistive RAM; vacancies (crystal); Hf1-xAl2xO2+x; HfO2; RRAM; ab initio techniques; alloying impact; atomic density; atomistic simulation; data retention; diffusion barrier calculations; electrical measurements; low resistance state retention; materials characterization; microscopic understanding; oxygen atoms; oxygen vacancy; Alloying; Atomic layer deposition; Atomic measurements; Hafnium compounds; Stability analysis; Switches; Thermal stability;
Conference_Titel :
Electron Devices Meeting (IEDM), 2014 IEEE International
DOI :
10.1109/IEDM.2014.7047097
