Nitrogen induced modifications of MANOS memory properties

N. Nikolaou (1) , V. Ioannou-Sougleridis (1) , P. Dimitrakis (1) , P. Normand (1) , D. Skarlatos (2) , K. Giannakopoulos (1) , S. Ladas (2) , Béatrice Pécassou (3) , Gérard Benassayag (3) , K. Kukli (4) , J. Niinistö (4) , M. Ritala (4) , M. Leskelä (4)

1 NCSR - National Center for Scientific Research "Demokritos"
2 University of Patras
3 CEMES - Centre d'élaboration de matériaux et d'études structurales
4 Helsingin yliopisto = Helsingfors universitet = University of Helsinki

In this work we examine the structural and electrical properties including the memory performance of Al2O3/Si3N4/SiO2 dielectric stacks implanted with low-energy nitrogen ions and subsequently thermal annealed at 850 or 1050 °C for 15 min. X-ray photoelectron spectroscopy reveals that the concentration and the chemical state of the nitrogen atoms within the Al2O3 layer depends on the post-implantation annealing (PIA) temperature. Memory testing, performed on platinum gate capacitors, shows that charge retention of the programmed states is significantly improved for the high-temperature PIA samples as compared to the non-implanted samples. While such an improvement is not detected for the low-temperature PIA samples, the latter exhibit enhanced hole charging and thus, increased erase efficiency. Overall, our results suggest that the transport properties which control the erase and the retention characteristics of the blocking Al2O3 layer can be tailored by nitrogen implantation and the PIA conditions and can be used for memory performance optimization.

Mots clés: Non-volatile memory; Postimplantation annealing; Retention characteristics; Structural and electrical properties; X ray photoelectron spectroscopy; Alumina; Aluminum; Charge trapping; Data storage equipment; Dielectric materials; Digital storage; Nitrogen; Temperature; Charge trapping memory; Low energy nitrogen; MANOS; Nitrogen implantation

Domaines: Physique [physics]

N. Nikolaou, V. Ioannou-Sougleridis, P. Dimitrakis, P. Normand, D. Skarlatos, et al.. Nitrogen induced modifications of MANOS memory properties. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms, 2015, 365, pp.61-65. ⟨10.1016/j.nimb.2015.04.015⟩. ⟨hal-01718634⟩