The dominant factors affecting the memory characteristics of (Ta2O5)x(Al2O3)1−x high-k charge-trapping devices

AbstractSemiconducting or metallic nanocrystals embedded high-k films have been investigated. They showed promising nonvolatile memory characteristics, such as low leakage currents, large charge storage capacities, and long retention times. Reliability of four different kinds of nanocrystals, i.e., nc- Ru, -ITO, -Si and -ZnO, embedded Zr-doped HfO2 high-k dielectrics have been studied. All of them have higher relaxation currents than the non-embedded high-k film has. The decay rate of the relaxation current is in the order of nc-ZnO > nc-ITO > nc-Si > nc-Ru. When the relaxation currents of the nanocrystals embedded samples were fitted to the Curie-von Schweidler law, the n values were between 0.54 and 0.77, which are much lower than that of the non embedded high-k sample. The nanocrystals retain charges in two different states, i.e., deeply and loosely trapped. The ratio of these two types of charges was estimated. The charge storage capacity and holding strength are strongly influenced by the type of material of the embedded nanocrystals. The nc-ZnO embedded film holds trapped charges longer than other embedded films do. The ramp-relax result indicates that the breakdown of the embedded film came from the breakdown of the bulk high-k film. The type of nanocrystal material influences the breakdown strength.

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Factors affecting the permeability of isolated fat-cells from the rat to [42K]potassium and [36Cl]chloride ions

Biochemical Journal ◽

10.1042/bj1170615 ◽

1970 ◽

Vol 117 (3) ◽

pp. 615-621 ◽

Cited By ~ 25

Author(s):

M. C. Perry ◽

C. N. Hales

Keyword(s):

Initial Phase ◽

Chloride Ions ◽

Fat Cells ◽

Adrenocorticotrophic Hormone ◽

Isolated Fat Cells ◽

Free Medium ◽

Fat Cell ◽

Factors Affecting ◽

Exchange Diffusion ◽

High K

1. The effluxes of 42K+ and 36Cl− from isolated fat-cells from the rat were studied under a variety of conditions known to affect the metabolism of the cells. 2. 42K+ efflux from isolated fat cells was increased in a Na+-free–high-K+ medium and decreased in a K+-free medium. The existence of K+ exchange diffusion across the fat-cell membrane is suggested. 3. 36Cl− efflux from isolated fat-cells was decreased when the Cl− component of the wash medium was replaced by acetate. The basal 36Cl− efflux is suggested to be partly by Cl− exchange diffusion and partly in company with a univalent cation. 4. A variety of lipolytic stimuli, adrenaline, adrenocorticotrophic hormone, N-6,O-2′-dibutyryladenosine cyclic 3′:5′-monophosphate and theophylline, increased 42K+ efflux from isolated fat-cells. The adrenaline stimulation was biphasic; an initial, rapid and transient increase in 42K+ loss from the fat-cells was followed by a slower, more prolonged, increase in 42K+ efflux. The initial phase was inhibited by phentolamine but not by propranolol. 5. Insulin increased 42K+ efflux only after preincubation with the cells.

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Temperature Influence on Nanocrystals Embedded High-k Nonvolatile Memory Characteristics

ECS Transactions ◽

10.1149/1.3118929 ◽

2019 ◽

Vol 19 (1) ◽

pp. 41-47

Author(s):

Chia-Han Yang ◽

Yue Kuo ◽

Chen-Han Lin ◽

Way Kuo

Keyword(s):

Nonvolatile Memory ◽

Temperature Influence ◽

High K ◽

Memory Characteristics

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Temperature-Dependent Physical and Memory Characteristics of Atomic-Layer-DepositedRuOxMetal Nanocrystal Capacitors

Journal of Nanomaterials ◽

10.1155/2011/810879 ◽

2011 ◽

Vol 2011 ◽

pp. 1-12 ◽

Cited By ~ 6

Author(s):

S. Maikap ◽

W. Banerjee ◽

T. C. Tien ◽

T. Y. Wang ◽

J. R. Yang

Keyword(s):

Gate Voltage ◽

Annealing Temperature ◽

Deep Level ◽

Charge Trapping ◽

Atomic Layer ◽

Memory Window ◽

Silicate Layer ◽

Metal Nanocrystals ◽

Annealing Temperatures ◽

Memory Characteristics

Physical and memory characteristics of the atomic-layer-depositedRuOxmetal nanocrystal capacitors in an n-Si/SiO2/HfO2/RuOx/Al2O3/Pt structure with different postdeposition annealing temperatures from 850–1000°C have been investigated. TheRuOxmetal nanocrystals with an average diameter of 7 nm and a highdensity of 0.7 × 1012/cm2are observed by high-resolution transmission electron microscopy after a postdeposition annealing temperature at 1000°C. The density ofRuOxnanocrystal is decreased (slightly) by increasing the annealing temperatures, due to agglomeration of multiple nanocrystals. The RuO3nanocrystals and Hf-silicate layer at the SiO2/HfO2interface are confirmed by X-ray photoelectron spectroscopy. For post-deposition annealing temperature of 1000°C, the memory capacitors with a small equivalent oxide thickness of ~9 nm possess a large hysteresis memory window of >5 V at a small sweeping gate voltage of ±5 V. A promising memory window under a small sweeping gate voltage of ~3 V is also observed due to charge trapping in theRuOxmetal nanocrystals. The program/erase mechanism is modified Fowler-Nordheim (F-N) tunneling of the electrons and holes from Si substrate. The electrons and holes are trapped in theRuOxnanocrystals. Excellent program/erase endurance of 106cycles and a large memory window of 4.3 V with a small charge loss of ~23% at 85°C are observed after 10 years of data retention time, due to the deep-level traps in theRuOxnanocrystals. The memory structure is very promising for future nanoscale nonvolatile memory applications.

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Nb2O5 and Ti-Doped Nb2O5 Charge Trapping Nano-Layers Applied in Flash Memory

Nanomaterials ◽

10.3390/nano8100799 ◽

2018 ◽

Vol 8 (10) ◽

pp. 799 ◽

Cited By ~ 1

Author(s):

Jer Wang ◽

Chyuan Kao ◽

Chien Wu ◽

Chun Lin ◽

Chih Lin

Keyword(s):

Flash Memory ◽

Charge Trapping ◽

Memory Device ◽

Dielectric Constants ◽

Oxide Semiconductor ◽

Flat Band ◽

Hysteresis Curve ◽

Band Shift ◽

K Value ◽

High K

High-k material charge trapping nano-layers in flash memory applications have faster program/erase speeds and better data retention because of larger conduction band offsets and higher dielectric constants. In addition, Ti-doped high-k materials can improve memory device performance, such as leakage current reduction, k-value enhancement, and breakdown voltage increase. In this study, the structural and electrical properties of different annealing temperatures on the Nb2O5 and Ti-doped Nb2O5(TiNb2O7) materials used as charge-trapping nano-layers in metal-oxide-high k-oxide-semiconductor (MOHOS)-type memory were investigated using X-ray diffraction (XRD) and atomic force microscopy (AFM). Analysis of the C-V hysteresis curve shows that the flat-band shift (∆VFB) window of the TiNb2O7 charge-trapping nano-layer in a memory device can reach as high as 6.06 V. The larger memory window of the TiNb2O7 nano-layer is because of a better electrical and structural performance, compared to the Nb2O5 nano-layer.

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