Articolo in rivista, 2018, ENG, 10.1021/acsanm.8b00918

Sub-1 nm Equivalent Oxide Thickness Al-HfO2 Trapping Layer with Excellent Thermal Stability and Retention for Nonvolatile Memory

Spiga, Sabina; Driussi, Francesco; Congedo, Gabriele; Wiemer, Claudia; Lamperti, Alessio; Cianci, Elena

Natl Res Council Italy CNR; Univ Udine; Univ Udine;

Memory stacks for charge trapping cells have been produced exploiting Al-doped Hfo(2), AL(2)O(3), and SiO2 made by atomic layer deposition. The fabricated stacks show superior stability and electrical characteristics, allowing for the engineering of sub-1 nm equivalent oxide thickness Al doped HfO2 trapping layer with excellent retention characteristics, also at high temperature. The low Al doping content (4.5%) used in this work leads to the HfO2 crystallization, upon thermal annealing, in the cubic/tetragonal phase with a dielectric constant value of 32. The trapping properties of the proposed stacks have been studied by means of physics-based models, highlighting the role of the different layers and the nature of the traps contributing to the charge storage in the memory stack.

ACS applied nano materials 1 (9), pp. 4633–4641

Keywords

charge trapping layer, nonvolatile memory, Al-doped-HfO2, SiO2, atomic layer deposition

CNR authors

Congedo Gabriele, Cianci Elena, Lamperti Alessio, Wiemer Claudia, Spiga Sabina

CNR institutes

IMM – Istituto per la microelettronica e microsistemi