Structural and electrical characteristics of high-k Tb2O3 and Tb2TiO5 charge trapping layers for nonvolatile memory applications

Abstract

In this study, we investigated the structural properties and electrical characteristics of metal/oxide/high-k material/oxide/silicon (MOHOS)-type memory devices incorporating Tb2O3 and Tb2TiO5 films as charge storage layers for nonvolatile memory applications. X-ray diffraction and x-ray photoelectron spectroscopy revealed the structural and chemical features of these films after they had been subjected to annealing at various temperatures. From capacitance-voltage measurements, we found that the MOHOS-type memory devices incorporating the Tb2TiO5 film and that had been annealed at 800 °C exhibited a larger flatband voltage shift of 2.94 V (Vg=9 V for 0.1 s) and lower charge loss of 8.5% (at room temperature), relative to those of the systems that had been subjected to other annealing conditions. This result suggests that Tb2TiO5 films featuring a thinner silicate layer and a higher dielectric constant provide a higher probability for trapping of the charge carrier and deeper electron trapping levels.

Tailoring the Electrical Properties of HfO2 MOS-Devices by Aluminum Doping

“…First, the values of the memory window Δ V C – V (5V) are used to assess N t . In metal-oxide-high-k dielectric-oxide-Si (MOHOS) structures, which are used for charge storage in charge trapping flash memories, the memory window is proportional to the spatial homogeneously trapped charge density (N t ; cm –3 ) and could be calculated by using the following equation: , where d OB and ε OB are the thickness and the dielectric constant of the blocking oxide in MOHOS, respectively. As in our structures there is not any blocking oxide, i.e., d OB = 0; the equation transforms to …”

“…First, the values of the memory window ΔV C−V (5V) are used to assess N t . In metal-oxide-high-k dielectric-oxide-Si (MOHOS) structures, which are used for charge storage in charge trapping flash memories, the memory window is proportional to the spatial homogeneously trapped charge density (N t ; cm −3 ) and could be calculated by using the following equation: 42,43…”

Structural and Lattice-Dynamical Properties of Tb2O3 under Compression: A Comparative Study with Rare Earth and Related Sesquioxides

“…These compounds are highly interesting and versatile for different types of applications because the Ln radius can be finely tuned along the lanthanide family with the filling of f orbitals, thus enabling a wide range of technological advances including light emitters (lasers and improved phosphors), catalysts, and high-dielectric constant (high-k) gates. In particular, terbium sesquioxide (Tb 2 O 3 ) has attracted considerable attention in the past few years as a high-k material − and also as an active material for optical insulators and high-performance optoelectronic devices. − …”

First principles investigation of structural, electronic, elastic and thermal properties of rare-earth-doped titanate Ln2TiO5

“…[1][2][3][4][5][6][7] The applications of Ln 2 TiO 5 compounds range from high-permittivity dielectrics, biomedical sensing [1][2][3][4][5][6][7] to nuclear reactor control rod materials [8][9][10] and nuclear waste forms. 11 Lanthanide oxides as alloying constituents can be used as neutron absorbers in control rods.…”