An Atomistic Study on Hydrogenation Effects toward Quality Improvement of Program/Erase Cycle of MONOS-Type Memory

Otake, Akira; Yamaguchi, Keita; Kamiya, Katsumasa; Shigeta, Yasuteru; Shiraishi, Kenji

doi:10.1587/transele.e94.c.693

Cited by 9 publications

(10 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During program/erase (P/E) cycles, the presence of defects will lead to reversible or irreversible structural change. The irreversible structural change is regarded as the explanation for CTM's endurance degeneration . To distinguish reversible change from irreversible change, we first compare the initial structure (S init ) and the structure after a P/E cycle (S final ).…”

Section: Methodsmentioning

confidence: 99%

Characterization of oxygen impurity in silicon nitride storage layer: A first-principles investigation

Luo

Hongpeng

et al. 2014

Phys. Status Solidi B

View full text Add to dashboard Cite

In this paper, based on first‐principles calculations, we have carried out a comprehensive study of substitutional oxygen defects in hexagonal silicon nitride (β‐Si3N4). First of all, it is found that substitutional oxygens tend to form clusters at three different sites due to the intensive attractive interaction. By analyzing modified Bader charge and trap energy, we next discuss retention characteristic of the three clusters. The results manifest that all of the clusters are amphoteric defects with the ability to trap both electrons and holes. Moreover, every cluster is more powerful to trap holes, which indicates that oxygen clusters have a higher stability to hold holes than electrons. With regard to endurance characteristic, our studies reveal that the three clusters present differences after program/erase cycles, and then we explore the mechanism of endurance degeneration by nudged elastic band method (NEB). Taking full account of retention and endurance, we deem holes rather than electrons to be optimal to act as operational charge carriers for oxygen defects in Si3N4‐based charge trapping memories.

show abstract

Section: Methodsmentioning

confidence: 99%

Characterization of oxygen impurity in silicon nitride storage layer: A first-principles investigation

Luo

Hongpeng

et al. 2014

Phys. Status Solidi B

View full text Add to dashboard Cite

show abstract

“…In recent years, a large number of literature points out that there are two types of structure changes induced by P/E cycles in CTM devices: reversible structural change and irreversible structural change, and the schematic illustration is shown in Fig. . The vertical coordinate is the energy in specific charged state and the

S_{i}

represents the initial state, and

S_{f}

represents the final state after a P/E cycle.…”

Section: Calculation Proceduresmentioning

confidence: 99%

“…and Otake et al. studies the impact of hydrogen in Si 3 N 4 layer on the MONOS‐type memory during P/E cycles . Post deposition annealing causes aluminum (Al) and oxygen (O) impurities diffusion into SiN trap layer in typical TANOS memory ().…”

Section: Introductionmentioning

confidence: 99%

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

Dai

Wang

et al. 2016

Physica Status Solidi (b)

View full text Add to dashboard Cite

Using hybrid density functional calculations, this paper systematically investigated the common defects in m‐HfO2 and β‐Si3N4 trapping layer, respectively, on the performance of charge trapping memory (CTM) devices. Defects may act as charge traps or fixed charges, however, only traps can be used to store charges. Thus, firstly, the paper distinguished traps or fixed charges of defects in trapping layer through the band alignment method. Then we can restrain the formation of defects that act as fixed charges in manufacturing CTM devices, which is very meaningful in improving the performance of CTM. Secondly, it studied the storage performance of traps in m‐HfO2 and β‐Si3N4 by analyzing the formation energy, the atomistic structural change during program/erase (P/E) cycles, and localization energy. The simulation results found that only some defects can be charge traps in m‐HfO2 and β‐Si3N4, and the charge transition of these traps only appeared between certain charged states. In addition, these traps show reversible structural change during P/E cycles and different localizing abilities for holes and electrons. Therefore, this study would provide some theoretical guidance for improving the performance of CTM.

show abstract

“…To investigate stable charged states for the present systems, we calculated formation energy (E form ) [3]. This is defined as a difference in total energy between systems A and B.…”

Section: Calculations Of Formation Energymentioning

confidence: 99%

“…One of merits of such memories is that they can trap charges inside very small atomistic regions such as defect sites in SiN layers, leading to the downsizing of nonvolatile memories. Recently, hydrogen has been recognized as an important heteroatom in MONOStype memories for its quality improvement [2,3]. In the conventional fabrication processes, it has been experimentally observed that H atoms are incorporated into the SiN layer [1].…”

Section: Introductionmentioning

confidence: 99%

First principle study of the stability of H atoms in SiN layers on MONOS-type memories during program/erase operations

Yamaguchi

Otake

Kamiya

et al. 2011

2011 International Conference on Simulation of Semiconductor Processes and Devices

Self Cite

View full text Add to dashboard Cite

Recently, hydrogen has been recognized as an important heteroatom in Metal-Oxide-Nitride-OxideSemiconductor (MONOS) -type memories for its quality improvement. However, if stability of H atoms in SiN layers changes by applying high voltage, memory characteristics of MONOS-type memories change during program/erase (P/E) operations, resulting in memory degradation. Therefore, in this paper, we have investigated the stability of H atoms in SiN charge trapping layers of MONOS-type memories during P/E operations by using first principles calculations. Our calculations show that H atoms in Si or N vacancies in SiN layers become unstable and migrate when high voltage is applied, leading to memory degradation with changes of memory characteristics. This result clearly indicates that suppression of H atoms in SiN layers is necessary for realization of high quality MONOS-type memories.

show abstract

An Atomistic Study on Hydrogenation Effects toward Quality Improvement of Program/Erase Cycle of MONOS-Type Memory

Cited by 9 publications

References 18 publications

Characterization of oxygen impurity in silicon nitride storage layer: A first-principles investigation

Characterization of oxygen impurity in silicon nitride storage layer: A first-principles investigation

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study

First principle study of the stability of H atoms in SiN layers on MONOS-type memories during program/erase operations

Contact Info

Product

Resources

About

An Atomistic Study on Hydrogenation Effects toward Quality Improvement of Program/Erase Cycle of MONOS-Type Memory

Cited by 9 publications

References 18 publications

Characterization of oxygen impurity in silicon nitride storage layer: A first-principles investigation

Characterization of oxygen impurity in silicon nitride storage layer: A first-principles investigation

Impact of native defects and impurities in m−HfO2 and β−Si3N4 on charge trapping memory devices: A first principle hybrid functional study

First principle study of the stability of H atoms in SiN layers on MONOS-type memories during program/erase operations

Contact Info

Product

Resources

About

Impact of native defects and impurities in m−HfO₂ and β−Si₃N₄ on charge trapping memory devices: A first principle hybrid functional study