Nucleation of Tungsten on Titanium Nitride with Hydrogen Reduction of Tungsten Hexafluoride

ABSTRACTIn this work, a hydrogen (H2) reduction process has been developed which gives tungsten (W) nucleation on titanium nitride (TiN) adhesion layers with a very short incubation time, eliminating the need for a silane (SiH4reduced seed layer. The nucleation was found to be strongly dependent on the following factors: temperature of the substrate, total pressure in chamber, and gas introduction sequence into the reactor. Theenhanced nucleation rate has been explained based on two competing reactions: dissociation of H2, and formation of titanium subfluorides on the TiN surface.

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Nanohole Coat/Fill with Pt via Chemical Deposition in Supercritical Fluids

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.617.184 ◽

2014 ◽

Vol 617 ◽

pp. 184-186

Author(s):

Eiichi Kondoh ◽

Toshiaki Goto ◽

Mitsuhiro Watanabe

Keyword(s):

Carbon Dioxide ◽

Supercritical Carbon Dioxide ◽

Supercritical Fluid ◽

Supercritical Fluids ◽

Incubation Time ◽

Seed Layer ◽

Noble Metals ◽

Hydrogen Reduction ◽

Chemical Deposition ◽

Nanostructure Formation

This paper demonstrates nanostructure formation performed by supercritical fluid chemical deposition. Pt was deposited through hydrogen reduction of a Pt chelate being dissolved in supercritical carbon dioxide. Pt was deposited conformally inside nanotrences, however Pt did not grow thick due to a very long incubation time for the nucleation. Interestingly, SFCD Pt grew thick on already-existing noble metals. A two-step SFCD process was employed, where a Pt seed layer was deposited first and Pt was grown thicker in the subsequent run. This enabled to fill Pt in nanotrenches and nanoholes.

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Copper Chemical Vapor Deposition using a Novel Cu(II) Precursor for Contact Via Filling Process

MRS Proceedings ◽

10.1557/proc-0990-b08-27 ◽

2007 ◽

Vol 990 ◽

Author(s):

Hideaki Zama ◽

Yuuji Nishimura ◽

Michiyo Yago ◽

Mikio Watanabe

Keyword(s):

Chemical Vapor Deposition ◽

Vapor Deposition ◽

Hydrogen Reduction ◽

Reduction Process ◽

Chemical Vapor ◽

Molar Ratio ◽

Cu Films ◽

Pure Cu ◽

Substrate Temperatures ◽

Advanced Generation

ABSTRACTChemical vapor deposition (CVD) of copper using both a novel Cu(II) β-diketonate source and hydrogen reduction process was studied to fill contact vias with the smallest diameter in the 32nm and more advanced generation chip. Pure Cu films were grown under the condition with the product of hydrogen partial pressure and H2/Cu source molar ratio being over 1,000,000. We succeeded in filling the 40-nm-diameter contact vias by optimizing the growth condition of the Cu-CVD in both substrate temperatures and reaction pressures.

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Selective High-Throughput TiN Etching Methods

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.195.143 ◽

2012 ◽

Vol 195 ◽

pp. 143-145 ◽

Cited By ~ 2

Author(s):

Emanuel I. Cooper ◽

Rekha Rajaram ◽

Makonnen Payne ◽

Steven Lippy

Keyword(s):

Titanium Nitride ◽

High Throughput ◽

Seed Layer ◽

Wet Etching ◽

Thermochemical Properties ◽

Hard Mask ◽

Acidic Solutions ◽

Layer Deposition ◽

Wet Etch ◽

Dry Etch

Titanium nitride (TiN) is widely used as a hard mask film protecting the inter-level dielectric (ILD) before metal or plating seed layer deposition steps. It is common practice to use a wet etch in order to remove residues formed during the ILD dry-etch step, and at the same time to remove some or all of the exposed TiN. From its thermochemical properties, it might be predicted that wet etching of TiN should be easy, since it is quite unstable with respect to both plain and oxidative hydrolysis. For example, in acidic solutions at 25°C [1, :

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Kinetics of synthesizing process for obtaining iron nanopowder by chemical-metallurgical method under isothermal conditions

Chernye Metally ◽

10.17580/chm.2021.01.11 ◽

2021 ◽

pp. 72-77

Author(s):

Tien Hiep Nguyen ◽

◽

Van Minh Nguyen ◽

Keyword(s):

Hydrogen Reduction ◽

Average Particle Size ◽

Chemical Deposition ◽

Reduction Process ◽

Nitrogen Adsorption ◽

Specific Rate ◽

Average Particle ◽

Isothermal Conditions ◽

Electron Microscopes ◽

Kinetics Of

In this work the kinetics of synthesizing process of metallic iron nanopowder by hydrogen reduction from α-FeOOH hydroxide under isothermal conditions were studied. α-FeOOH nanopowder was prepared in advance by chemical deposition from aqueous solutions of iron nitrate Fe(NO3)3 (10 wt. %) and alkali NaOH (10 wt. %) at room temperature, pH = 11, under the condition of continuous stirring. The hydrogen reduction process of α-FeOOH nanopowder under isothermal conditions was carried out in a tube furnace in the temperature range from 390 to 470 °C. The study of the crystal structure and composition of the powders was performed by X-ray phase analysis. The specific surface area S of the samples was measured using BET method by low-temperature nitrogen adsorption. The average particle size D of powders was determined via the measured S value. The size characteristics and morphology of the particles were investigated by transmission and scanning electron microscopes. The calculation of the kinetic parameters of the hydrogen reduction process of α-FeOOH under isothermal conditions was carried out by the Gray-Weddington model and Arrhenius equation. It is shown that the rate constant of reduction at 470 °C is approximately 2.2 times higher than in the case at 390 °C. The effective activation energy of synthesizing process of iron nanopowder by hydrogen reduction from α-FeOOH was ~38 kJ/mol, which indicates a mixed reaction mode. In this case, the kinetics overall process is limited by both the kinetics of the chemical reaction and the kinetics of diffusion, respectively, an expedient way to accelerate the process by increasing the temperature or eliminate the diffusion layer of the reduction product by intensive mixing. It is show that Fe nanoparticles obtained by hydrogen reduction of its hydroxide at 410 °C, corresponding to the maximum specific rate of the reduction process, are mainly irregular in shape, evenly distributed, the size of which ranges from several dozens to 100 nm with an average value of 75 nm.

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Kinetic study on preparation of substoichiometric tungsten oxide WO2.72 via hydrogen reduction process

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-018-7966-4 ◽

2018 ◽

Vol 137 (2) ◽

pp. 389-397 ◽

Cited By ~ 3

Author(s):

Dan Qiao ◽

Yue Wang ◽

Fan Li ◽

Daya Wang ◽

Baijun Yan

Keyword(s):

Kinetic Study ◽

Tungsten Oxide ◽

Hydrogen Reduction ◽

Reduction Process

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The influence of the hydrogen reduction process on the electrical properties of In2O3:Sn thin films

Thin Solid Films ◽

10.1016/0040-6090(83)90481-9 ◽

1983 ◽

Vol 106 (3) ◽

pp. 195-202 ◽

Cited By ~ 4

Author(s):

T. Horodyski ◽

K. Budzynska ◽

E. Leja

Keyword(s):

Thin Films ◽

Electrical Properties ◽

Hydrogen Reduction ◽

Reduction Process

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Immunoradiometric assay with use of magnetizable particles: measurement of thyrotropin in blood spots, to screen for neonatal hypothyroidism.

Clinical Chemistry ◽

10.1093/clinchem/32.10.1966 ◽

1986 ◽

Vol 32 (10) ◽

pp. 1966-1968 ◽

Cited By ~ 11

Author(s):

K V Waite ◽

G F Maberly ◽

G Ma ◽

C J Eastman

Keyword(s):

Incubation Time ◽

Separation Procedure ◽

Immunoradiometric Assay ◽

Assay Sensitivity ◽

Neonatal Hypothyroidism ◽

Blood Spots ◽

Standard Curve ◽

Coefficients Of Variation ◽

Specialized Equipment ◽

Short Incubation Time

Abstract We adapted a commercial immunoradiometric assay (IRMA) to measure thyrotropin in filter-paper blood spots. Two 3-mm blood spots are used for each standard and sample. These are incubated for 2 h with radiolabeled antibody and for 30 min with magnetic antibody, followed by a 10-min separation procedure. Assay sensitivity is 6 milli-int. units/L. Coefficients of variation (precision profile of the standard curve) ranged from 4.3 to 9.6%. The coefficient of correlation (r) between thyrotropin concentrations in the blood spots and in serum was 0.93. Pre-elution of the blood spots is necessary for short incubation time. Short incubation time, little need for specialized equipment, the high precision and sensitivity characteristic of IRMA, and ease of collection, transport, and storage of the blood-spot samples make this assay suitable for neonatal hypothyroid screening.

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Use of Iron Milk Medium for Enumeration of Clostridium perfringens

Journal of AOAC INTERNATIONAL ◽

10.1093/jaoac/65.5.1129 ◽

1982 ◽

Vol 65 (5) ◽

pp. 1129-1133 ◽

Cited By ~ 2

Author(s):

William D St John ◽

Jack R Matches ◽

Marleen M Wekell

Keyword(s):

Clostridium Perfringens ◽

Incubation Time ◽

Incubation Temperature ◽

Egg Yolk ◽

Most Probable Number ◽

Biochemical Tests ◽

Probable Number ◽

Large Numbers ◽

Whole Milk ◽

Short Incubation Time

Abstract A simple iron milk medium was used for isolation and enumeration of Clostridium perfringens from soil, sludge, and water samples. The whole milk contained only iron powder as a reducing agent; no other inhibitors were added. The iron milk most probable number (MPN) procedure was compared with 4 plating media: sulfite-polymyxin-sulfadiazine, Shahidi-Ferguson perfringens, tryptose-sulfite- cycloserine (both with and without egg yolk), and tryptone-sulfite-neomycin. The selectivity of the iron milk relies solely on the rapid growth of C. perfringens at 45°C and the stormy fermentation reaction within 18 h. Isolates were confirmed as C. perfringens by standard biochemical tests. The iron milk MPN procedure compared very well with the 4 plating media tested. Selectivity of incubation temperature, short incubation time, and ease of identification by the characteristic stormy fermentation make this method ideal for enumerating C. perfringens from large numbers of samples.

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A Novel Process for the Synthesis of NaV2O5 Mesocrystals from Alkaline-Stripped Vanadium Solution via the Hydrothermal Hydrogen Reduction Method

Minerals ◽

10.3390/min9050271 ◽

2019 ◽

Vol 9 (5) ◽

pp. 271

Author(s):

Guobin Zhang ◽

Yimin Zhang ◽

Shenxu Bao ◽

Liuhong Zhang

Keyword(s):

Electron Microscopy ◽

Hydrogen Reduction ◽

Ph Value ◽

Hydrothermal Process ◽

Reduction Process ◽

Oriented Attachment ◽

Synthesis Process ◽

Synthesis Mechanism ◽

Time Saving ◽

Synthesis Time

NaV2O5 mesocrystals were successfully synthesized from an alkaline-stripped pentavalent vanadium solution through a novel hydrothermal hydrogen reduction process. The optimal conditions for the hydrogen partial pressure, reaction temperature, initial solution pH value, and reaction time for the pure-phase NaV2O5 synthesis were ascertained to be 4 MPa, 200 °C, 4.0, and 2 h, respectively. The synthesis time (only 2 h) was greatly shortened, by nine times, compared with the most time-saving (18 h) hydrothermal process at present. X-ray diffraction (XRD) analysis revealed that the as-prepared powders demonstrated a typical layered orthorhombic structure of NaV2O5. The purity of the as-prepared NaV2O5 reached up to 99.98%. An electrochemical test showed that the as-prepared NaV2O5 has a potential application in sodium ion batteries. According to scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses, the as-prepared NaV2O5 powders were identified to have rod-like mesocrystals consisting of small rods which preferentially grow along the (010) direction. Furthermore, the phase transformation mechanism and crystal growth mechanism in NaV2O5 preparation were discussed systematically, based on which the synthesis mechanism of NaV2O5 was proposed as pentavalent vanadates pre-sedimentation, hydrogen reduction with dehydration, sodium ions insertion, and finally self-assembly oriented attachment. The synthesis process is characterized as time-saving and low-cost, and thus it may have great application prospects.

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