High K-value LDD GaAs MESFET's with SiF/sub 3/-implanted shallow channels

AbstractBecause of aggressive downscaling to increase transistor performance, the physical thickness of the SiO2 gate dielectric is rapidly approaching the limit where it will only consist of a few atomic layers. As a consequence, this will result in very high leakage currents due to direct tunneling. To allow further scaling, materials with a k-value higher than SiO2 (“high-k materials”) are explored, such that the thickness of the dielectric can be increased without degrading performance.Based on our experimental results, we discuss the potential of MOCVD-deposited HfO2 to scale to (sub)-1-nm EOTs (Equivalent Oxide Thickness). A primary concern is the interfacial layer that is formed between the Si and the HfO2, during the MOCVD deposition process, for both H-passivated and SiO2-like starting surfaces. This interfacial layer will, because of its lower k-value, significantly contribute to the EOT and reduce the benefit of the high-k material. In addition, we have experienced serious issues integrating HfO2 with a polySi gate electrode at the top interface depending on the process conditions of polySi deposition and activation anneal used. Furthermore, we have determined, based on a thickness series, the k-value for HfO2 deposited at various temperatures and found that the k-value of the HfO2 depends upon the gate electrode deposited on top (polySi or TiN).Based on our observations, the combination of MOCVD HfO2 with a polySi gate electrode will not be able to scale below the 1-nm EOT marker. The use of a metal gate however, does show promise to scale down to very low EOT values.

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Data normalization for training and analysis of the MaskRCNN model using the k-means method for computer vision of smart refrigerator

Informatization and communication ◽

10.34219/2078-8320-2021-12-4-74-80 ◽

2021 ◽

Vol 4 ◽

pp. 74-80

Author(s):

M. G. Dorrer ◽

◽

A.E. Alekhina ◽

Keyword(s):

Computer Vision ◽

Semantic Segmentation ◽

Correct Choice ◽

Training Sample ◽

Artificial Vision ◽

K Value ◽

High K ◽

Real World Datasets ◽

Segmentation Problem

This paper proposes using the k-means method for the controlled adjustment of the training sample for semantic image segmentation in the artificial vision of a smart refrigerator. To solve this problem, a new two-stage architecture for computer vision is proposed. In the proposed architecture, various sets of settings for optimizing the contrast of images are used to classify pixels according to their belonging to fragments of the studied image. Extensive experimental evaluation shows that the proposed method has critical advantages over existing work. Firstly, the obtained pixel classes can be directly clustered into semantic groups using k-means. Secondly, the method can be used for additional training of artificial intelligence in solving the semantic segmentation problem. The developers propose an approach to the correct choice of the number k of centroids to obtain good quality clusters, which is difficult to determine at a high k value. To overcome the problem of initializing the k-means method, an incremental k-means clustering method is proposed, which improves the quality of clusters to reduce the sum of squared errors. Comprehensive experiments have been carried out compared to the traditional k-means algorithm and its new versions to evaluate the performance of the proposed method on synthetically generated datasets and some real-world datasets.

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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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Hydrogen Diffusion Coefficient, Hydrogen Solution Coefficient and Hydrogen Permeability of Nb-TiNi Eutectic Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.638-642.1131 ◽

2010 ◽

Vol 638-642 ◽

pp. 1131-1136

Author(s):

Wei Liang Wang ◽

Kazuhiro Ishikawa ◽

Kiyoshi Aoki

Keyword(s):

Diffusion Coefficient ◽

Hydrogen Absorption ◽

Hydrogen Diffusion ◽

Hydrogen Permeability ◽

K Value ◽

Hydrogen Flow ◽

Hydrogen Diffusion Coefficient ◽

High K ◽

Pressure Region ◽

The Difference

In general, hydrogen permeabilityΦ of the alloy membrane is expressed as the product of the hydrogen diffusion coefficient D and the hydrogen solution coefficient K. Therefore, to improve the hydrogen permeability efficiently, the values of K and D should be separately considered. In the present study, hydrogen absorption and permeation behaviors of the Nb19Ti40Ni41 alloy consisting of the eutectic phase are investigated by measuring pressure-composition-isotherm (PCI) and by the hydrogen flow method and compared with those of palladium. The hydrogen absorption in the Nb19Ti40Ni41 alloy does not obey the Sieverts’ law in the pressure region of 0-1.0MPa at 523K, but it shows linear relationship between the difference in the square root of hydrogen pressure and hydrogen content between 0.1 and 0.4MPa. Although the value of D for the Nb19Ti40Ni41 alloy is considerably lower than that of palladium, its high K value enhances the hydrogen permeability Φ. It is suggested that the enhancement of D by microstructural control for Nb19Ti40Ni41 alloy is effective for improvement of Φ.

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Physical-Chemical Evolution of Hf-aluminates upon Thermal Treatments

MRS Proceedings ◽

10.1557/proc-765-d2.10 ◽

2003 ◽

Vol 765 ◽

Author(s):

B. Crivelli ◽

M. Alessandri ◽

S. Alberici ◽

D. Brazzelli ◽

A. C. Elbaz ◽

...

Keyword(s):

Orthorhombic Phase ◽

Interface Layer ◽

Film Structure ◽

Thermal Treatments ◽

Tem Analysis ◽

K Value ◽

Physical Chemical ◽

High K ◽

Post Deposition ◽

Limited Oxygen

AbstractThis study presents an investigation on physical-chemical stability of (HfO2)x(Al2O3 )1-x alloys upon prolonged post-deposition annealings. Two different Hf-aluminates were deposited by ALCVDTM, containing 34% and 74% Al2O3 mol% respectively. Post-deposition annealings (PDA) were carried out in O2 or N2 atmosphere, at 850°C and 900°C for 30 minutes. Interfacial layer (IL) increase after PDA was detected on all the samples, but with small differences between N2 and O2 treatments. Stack composition was characterized by means of XRR, XRF, RBS and TOF-SIMS. Growth of interface layer was justified by limited oxygen incorporation from external ambient. Silicon diffusion from the substrate into high-k material and aluminum/hafnium redistribution were observed and associated to annealing temperature. XRD and planar TEM analysis evidenced first grain formation and then, in the case of Hf-rich samples, almost complete crystallization. Overall, Hf-aluminates were found to remain XRD amorphous during high temperature prolonged treatments up to 900°C for 74% and 850°C for 34% alloys respectively. Differently from HfO2, (HfO2)0.66(Al2O3 )0.34 alloy was observed to crystallized in orthorhombic phase. Hf-aluminates were also electrically characterized by means of C(V) and I(V) measurements on basic capacitors. Variations in material electrical properties were found consistent with change in physical-chemical film structure. Increase in k value up to 30 was observed on Hf-rich samples crystallized in orthorhombic phase.

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Scaling of Hafnium-based High-k Dielectrics

MRS Proceedings ◽

10.1557/proc-0996-h03-01 ◽

2007 ◽

Vol 996 ◽

Cited By ~ 2

Author(s):

Dina H. Triyoso ◽

Rama I. Hegde ◽

Rich Gregory ◽

David C. Gilmer ◽

James K. Schaeffer ◽

...

Keyword(s):

Dielectric Constant ◽

Threshold Voltage ◽

Tetragonal Phase ◽

Minimum Thickness ◽

Equivalent Thickness ◽

K Value ◽

Good Thermal Stability ◽

Bilayer Films ◽

High K ◽

High Dielectric

AbstractIn this paper, various approaches to extend scalability of Hafnium-based dielectrics are reported. Among the three crystal phases of HfO2 (monoclinic, cubic and tetragonal), the tetragonal phase has been reported to have the highest dielectric constant. Tetragonal phase stabilization by crystallizing the thin HfO2 using a metal capping layer and by adding zirconium is demonstrated. The microstructure, morphology, optical properties and impurities of HfxZr1-xO2 dielectrics (for 0<x<1) are discussed. Subtle but important modification to high-k / Si interface characteristics resulting from addition of Zr into HfO2 is reported. To further boost the dielectric constant of hafnium-based dielectrics, incorporation of TiO2, which has been reported to have high dielectric constant, is explored. HfxZr1-xO2/TiO2 bilayer films were fabricated. 30 Å TiO2 films were deposited on a 5, 8, 12 or 15 Å HfxZr1-xO2 underlayer to determine the minimum thickness needed to maintain good thermal stability with Si substrate. CV and IV results indicated that 12-15 Å is the optimal thickness range for the HfxZr1-xO2 underlayer. A dielectric constant as high as 150 for TiO2 layer is extracted from TiO2 thickness series deposited on12 Å HfxZr1-xO2 underlayer. In addition to increasing the k-value of Hafnium-based dielectrics, it is important that the threshold voltage of these high-k devices is low. Here we report the use of thin Al2O3 capping layers to modulate PMOS threshold voltages. About 100 mV reduction in threshold voltage is achieved by capping HfO2 with a 5Å Al2O3 film. Finally, dielectric scaling by modifying the Si/high-k interfacial layer is attempted. Nitrogen incorporation into HfxZr1-xO2 is shown to be a simple and effective method to lower the capacitance equivalent thickness (CET) of Hafnium-based dielectrics.

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Effect of oxygen tension and rate of pressure reduction during decompression on central gas bubbles

Journal of Applied Physiology ◽

10.1152/jappl.1998.84.1.351 ◽

1998 ◽

Vol 84 (1) ◽

pp. 351-356 ◽

Cited By ~ 7

Author(s):

R. E. Reinertsen ◽

V. Flook ◽

S. Koteng ◽

A. O. Brubakk

Keyword(s):

Pulmonary Artery ◽

Partial Pressure ◽

Oxygen Tension ◽

Decompression Sickness ◽

Gas Bubbles ◽

Pressure Reduction ◽

K Value ◽

Decompression Rate ◽

High K ◽

Effect Of Oxygen

Reinertsen, R. E., V. Flook, S. Koteng, and A. O. Brubakk.Effect of oxygen tension and rate of pressure reduction during decompression on central gas bubbles. J. Appl. Physiol. 84(1): 351–356, 1998.—Reduction in ascent speed and an increase in the O2 tension in the inspired air have been used to reduce the risk for decompression sickness. It has previously been reported that decompression speed and O2 partial pressure are linearly related for human decompressions from saturation hyperbaric exposures. The constant of proportionality K( K = rate/partial pressure of inspired O2) indicates the incidence of decompression sickness. The present study investigated the relationship among decompression rate, partial pressure of inspired O2, and the number of central gas bubbles after a 3-h dive to 500 kPa while breathing nitrox with an O2 content of 35 kPa. We used transesophageal ultrasonic scanning to determine the number of bubbles in the pulmonary artery of pigs. The results show that, for a given level of decompression stress, decompression rate and O2 tension in the inspired air can be traded off against each other by using pulmonary artery bubbles as an end point. The results also seem to confirm that decompressions that have a high K value are more stressful.

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Effect of Top Dielectric Morphology and Gate Material on the Performance of Nitride-based FLASH Memory Cells

MRS Proceedings ◽

10.1557/proc-1071-f02-08 ◽

2008 ◽

Vol 1071 ◽

Author(s):

Antonio Cacciato ◽

Laurent Breuil ◽

Geert Van den bosch ◽

Olivier Richard ◽

Aude Rothschild ◽

...

Keyword(s):

Fermi Level ◽

Morphological Changes ◽

Electron Injection ◽

Nitride Layer ◽

Device Fabrication ◽

Morphological Transformation ◽

K Value ◽

Fermi Level Pinning ◽

High K ◽

High K Dielectric

AbstractThe nitride-based SONOS cell, for its excellent scalability and process simplicity, is the candidate to push the scaling roadmap for FLASH memories beyond the limit imposed on floating-gate memories by the electrostatic interference between adjacent cells. The traditional SONOS cell consists of a nitride layer (the storage element) encapsulated by two SiO2 layers which isolate the nitride layer from the Si substrate and the poly-Si gate (Poly-Si/SiO2/Si3N4/SiO2/c-Si). However, the thick tunnel oxide necessary to meet the retention requirements imposes a severe limit on the erase performance because of the erase saturation phenomenon. One possibility to guarantee both the erase and the retention performance is the replacement of the top SiO2 layer with materials of higher dielectric constant (high-k dielectric). The presence of a high-k dielectric reduces the electric field across the top dielectric, thus decreasing the unwanted parasitic electron injection from the gate during the erase operation. This will allow the cell to erase deep so to meet a basic requirement for Gigabit multilevel NAND memories. The introduction of high-k materials in the SONOS stack is unfortunately not straightforward. One problem is the Fermi-level pinning at the poly-Si/high-k interface. Another problem is the morphological changes the high-k material undergoes during the device fabrication thermal budget. These changes can modify the k-value and affect the band offset between gate and high-k material. The results may, in both cases, be the decrease of the barrier for electron injection from the gate and, as a consequence, the deterioration of the erase performance. In this paper we study the effect of gate material and of the morphological transformation associated with the high-k post deposition anneal on the erase and the retention behaviour of nitride-based cells. Two different high-k dielectrics are investigated: Al2O3 (which has already been found to be able to significantly improve the erase operation, guaranteeing at the same time excellent endurance and sufficient bake retention) and HfAlO. We show that both for Al2O3 and HfAlO a trade-off exists between erase and retention, higher PDA temperatures being beneficial for erase but detrimental for retention. We also discuss the effect of Fermi level pinning and poly-Si depletion on the erase behaviour and compare the erase performances of several PVD- and AVD-deposited metal gates.

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Engineering the nm-thick Interface Layer Formed Between a High-k Film and Silicon

MRS Proceedings ◽

10.1557/proc-811-d3.11 ◽

2004 ◽

Vol 811 ◽

Author(s):

J. Lu ◽

J. -Y. Tewg ◽

Y. Kuo

Keyword(s):

Charge Density ◽

Layer Structure ◽

Charge Trapping ◽

Dielectric Strength ◽

Interface Layer ◽

Fixed Charge ◽

K Value ◽

Fixed Charge Density ◽

Hafnium Nitride ◽

High K

ABSTRACTThe interface layer between thin sputter-deposited tantalum oxide (TaOx) high-k film and silicon substrate was engineered with the Hf doping method and the insertion of a thin 5Å TaNx interface. The following results have been obtained: 1) the Hf dopant in the TaOx film was involved in the interface formation process, e.g., forming a new, thinner high-k HfSixOy interface layer rather than the SiOx layer, 2) when the TaNx interface was inserted, the interface layer composition was even more complicated, e.g., including TaOxNy and HfSixOy structures. No hafnium nitride or oxynitride was detected, 3) the interface layer structure was changed, e.g., from single-zone to multi-zone with different compositions, 4) when a low concentration of Hf existed in the TaOx film, the high-k dielectric properties, such as the k value, fixed charge density, dielectric strength, were improved, and 5) when the thin TaNx interface layer was inserted, the above electric properties were further improved. However, the fixed charge density and interface states were increased due to the insertion of the TaNx interface layer. These results were contributed by factors such as the charge-trapping characteristics in the interface layer and the some damage repairing mechanisms. In summary, this research proved that the high-k film's interface layer and bulk properties could be were improved with the doping process as well as the insertion of an ultra-thin TaNx interface film.

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Analysis of ZrxSiyOz as High-k Dielectric for 4H-SiC MOSFETs

Materials Science Forum ◽

10.4028/www.scientific.net/msf.924.939 ◽

2018 ◽

Vol 924 ◽

pp. 939-942 ◽

Cited By ~ 1

Author(s):

Maria Cabello ◽

Aneesha Varghese ◽

Josep Montserrat ◽

José Rebollo ◽

Jean Manuel Decams ◽

...

Keyword(s):

Thermodynamic Stability ◽

Gate Dielectric ◽

Interface Quality ◽

K Value ◽

High K ◽

High K Dielectric ◽

Process Compatibility

This paper deals with investigation and fabrication of 4H-SiC MOSFETs with a high-k dielectric close to ZrSiO4. We are looking for the optimal stochiometry in order to obtain full benefits of its large bandgap, a k value higher than that of SiO2, thermodynamic stability on SiC, a good interface quality and process compatibility with SiC technology. Several Si/Zr ratios have been tested with the purpose of obtaining the most favorable dielectric configuration. The first test devices have been manufactured successfully with a stack gate dielectric consisting of a thin SiO2interlayer and a ZrxSiyOz(theoretical Si/Z=0.7) layer on top.

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