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

Abstract

Memory stacks for charge trapping cells have been produced exploiting Al-doped HfO2, Al2O3, 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.

Composite Memristors by Nanoscale Modification of Hf/Ta Anodic Oxides

“…Oxides of valve metals have shown remarkable performances as memristive elements. − Studies on Hf- and Ta-based memristors reported excellent electrical and memory properties, such as multilevel switching, high endurance, and data retention. , The deposition of oxide layers is commonly done by atomic layer deposition , or sputtering . Alternatively, the electrochemical anodization process is a faster, less complex, and inexpensive method, with precise composition and oxide thickness control through electrochemical parameters. , …”

Synaptic plasticity and non-volatile memory characteristics in TiN-nanocrystal-embedded 3D vertical memristor-based synapses for neuromorphic systems

“…[26][27][28][29][30][31] Of these, HfO x is CMOS compatible and offers many benefits, including a high dielectric constant (∼25) and a wide bandgap (∼6 eV). 32,33 Moreover, HfO x -based RRAM relies on the formation and rupture of conductive filaments, which are produced by the migration of oxygen vacancies within the switching layer. 34,35 Accordingly, it is important to determine the factors that improve reliability (especially in vertically stacked structures), because it is challenging within RRAM to handle the intrinsically and stochastically generated filaments.…”

Мемристоры на основе поли-n-ксилилена с внедренными наночастицами серебра

“…Большинство мемристивных устройств на данный момент изготавливается с использованием неорганических материалов (TiO 2 , ZnO, HfO 2 , WO 3 , SiO 2 и др.) [6][7][8][9]. Наряду с неорганическими мемристорами все больший интерес начинают вызывать мемристоры на основе органических материалов, так как они не уступают неорганическим по основным параметрам [10], но при этом обладают рядом преимуществ, например относительно малой стоимостью, простотой изготовления, гибкостью и биосовместимостью [11,12].…”