Open AccessElectrical characterization of memory capacitors for nonvolatile memory applications based on nanolaminated HfO2/Al2O3 and Al-doped HfO2 stacks
Author(s) -
D. Spassov,
A. Paskaleva,
T Stanchev,
Tzvetan Ivanov
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2240/1/012046
Subject(s) - materials science , capacitor , doping , dielectric , analytical chemistry (journal) , high κ dielectric , stack (abstract data type) , capacitance , oxide , optoelectronics , non volatile memory , voltage , electrical engineering , electrode , chemistry , chromatography , computer science , metallurgy , programming language , engineering
Memory capacitors with atomic-layer-deposited HfO 2 /Al 2 O 3 nanolaminated layers and Al-doped HfO 2 charge trapping layers were investigated through capacitance-voltage ( C-V ) and current-voltage ( I-V ) measurements. The dielectric constant of the multi-dielectric stack comprising 20-nm Al 2 O 3 blocking oxide, a HfO 2 -based layer and 2.4-nm tunnel SiO 2 does not depend on the manner of Al-introduction in HfO 2 .The stacks exhibit a negative oxide charge of about -5.1×10 11 cm −2 and -2.5×10 11 cm −2 for the structures with nanolaminated and doped layers, respectively. The Al-doping of HfO 2 is found to produce lower leakage currents. A sublinear behavior of the current-voltage curves is observed in the range of -20 ÷ +10 V for both HfO 2 -based stacks. Memory windows of ∼ 1 V when charging with ±27-V voltage pulses are obtained; the data suggests that electron trapping is better pronounced in the HfO 2 /Al 2 O 3 nanolaminate, while positive charge accumulation prevails in the Al-doped HfO 2 layers.