Local electrochemical deposition of Ni into vertical vias in Si/SiO2 substrate

Ni electrochemical deposition into a matrix of various diameters (500–2000 nm) vertical vias in Si/SiO2 substrates with a barrier layer at the vias’ bottom has been investigated. Morphological study of Ni deposits in the vias showed they are deposited directly on the surface of the barrier layer. Repeatability and stability in combination with a homogeneous structure and 70% filling degree of vias determine the prospects of the Si/SiO2/Ni system as a basic element for the creation of three-dimensional micro-, nanostructures, and 3D assembly of IC crystals

Study of the Thermal Stability of Copper Contact Junctions in Si/SiO2 Substrates

The results of a comprehensive study of the structural- morphological and thermodynamic characteristics of the electrochemical precipitation of Cu in transition holes with a barrier layer of TiN in Si/SiO2 substrates by scanning electron microscopy (SEM) and differential thermal analysis (DTA) are presented. The temperature range that determines the heat resistance of copper (up to 750°C) and the temperature range (up to 886°C) that determines the thermal stability of the composite as a whole, as well as the ability to maintain the chemical composition and ordered structure at elevated temperatures, are found

Studying the Thermodynamic Properties of Composite Magnetic Material Based on Anodic Alumina

Magnetic nanoparticles based on Fe3O4 and their modifications of surface with therapeutic substances are of great interest, especially drug delivery for cancer therapy includes boron-neutron capture therapy. In this paper we study the thermodynamic, morphological, structural, and chemical properties of a composite material consisting of nickel nanowires (NWs) electrochemically deposited in the pores of the membrane of porous anodic aluminum oxide (PAA) by methods of differential thermal analysis (DTA), scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), and dispersive X-ray spectroscopy (EDX)

Magnetic Properties of the Densely Packed Ultra-Long Ni Nanowires Encapsulated in Alumina Membrane

High-quality and compact arrays of Ni nanowires with a high ratio (up to 700) were obtained by DC electrochemical deposition into porous anodic alumina membranes with a distance between pores equal to 105 nm. The nanowire arrays were examined using scanning electron microscopy, X-ray diffraction analysis and vibration magnetometry at 300 K and 4.2 K. Microscopic and X-ray diffraction results showed that Ni nanowires are homogeneous, with smooth walls and mostly single-crystalline materials with a 220-oriented growth direction. The magnetic properties of the samples (coercivity and squareness) depend more on the length of the nanowires and the packing factor (the volume fraction of the nanowires in the membrane). It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. The effect of magnetostatic interaction between ultra-long nanowires (with an aspect ratio of >500) in samples with a packing factor of ≥37% leads to a reversal magnetization state, in which a “curling”-type model of nanowire behavior is realized. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: An.T. (Andrei Turutin) acknowledges the financial support of the Russian Science Foundation (Grant No. 19-79-30062) in part of the experimental work. A.K. (Alexander Kislyuk) and I.K. (Ilya Kubasov) acknowledge the financial support of the Ministry of Science and Higher Education of the Russian Federation as a part of the State Assignment (basic research, Project No. 0718-2020-0031 “New magnetoelectric composite materials based on oxide ferroelectrics having an ordered domain structure: production and properties”) in part of the XRD study

Magnetic Properties of the Densely Packed Ultra-Long Ni Nanowires Encapsulated in Alumina Membrane

High-quality and compact arrays of Ni nanowires with a high ratio (up to 700) were obtained by DC electrochemical deposition into porous anodic alumina membranes with a distance between pores equal to 105 nm. The nanowire arrays were examined using scanning electron microscopy, X-ray diffraction analysis and vibration magnetometry at 300 K and 4.2 K. Microscopic and X-ray diffraction results showed that Ni nanowires are homogeneous, with smooth walls and mostly single-crystalline materials with a 220-oriented growth direction. The magnetic properties of the samples (coercivity and squareness) depend more on the length of the nanowires and the packing factor (the volume fraction of the nanowires in the membrane). It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. The effect of magnetostatic interaction between ultra-long nanowires (with an aspect ratio of >500) in samples with a packing factor of ≥37% leads to a reversal magnetization state, in which a “curling”-type model of nanowire behavior is realized. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: An.T. (Andrei Turutin) acknowledges the financial support of the Russian Science Foundation (Grant No. 19-79-30062) in part of the experimental work. A.K. (Alexander Kislyuk) and I.K. (Ilya Kubasov) acknowledge the financial support of the Ministry of Science and Higher Education of the Russian Federation as a part of the State Assignment (basic research, Project No. 0718-2020-0031 “New magnetoelectric composite materials based on oxide ferroelectrics having an ordered domain structure: production and properties”) in part of the XRD study

Metallization of Vias in Silicon Wafers to Produce Three-Dimensional Microstructures

The processes of electrochemical deposition into a matrix of vertical vias of different diameters (500–2000 nm) in Si/SiO2 substrates with a TiN barrier layer at the bottom of the holes are studied. Morpho- logical studies of the metal in the holes show that the structure of copper clusters is rather uniform and is formed from crystallites of ~30 to 50 nm. Repeatability and stability with a homogeneous structure and with holes filled 100% by Cu determine the prospect of using the Si/SiO2/Cu system as a basic element for creating three-dimensional micro- and nanostructures, as well as for the 3D assembly of IC crystals

Formation and corrosion properties of Ni-based composite material in the anodic alumina porous matrix

Ni nanopillars (Ni NPs) composite material formation technology embedded in porous anodic alumina by electrochemical deposition is presented in this paper. The morphological and structural properties of the composite material were investigated using scanning electron microscopy, atomic force microscopy, X-ray diffraction. The corrosion resistance of the nanocomposite materials has been studied by potentiodynamic polarization curves analysis and polarization resistance method. The composite represents the array of vertically ordered Ni NPs with the identical size in alumina matrix. XRD investigation indicates that Ni NPs are polynanocrystalline material with 18 nm crystallite size. It has been shown that Ni NPs and the composite material have sufficient corrosion resistance in a 0.9% aqueous NaCl solution. Porous alumina is the neutral and protective component of the composite. These nanocomposite materials can be excellent candidates for practical use in electronics, sensorics, biomedicine

Immobilization of boron-rich compound on Fe3O4 nanoparticles: Stability and cytotoxicity

Magnetic nanoparticles based on Fe3O4 and their modifications of surface with therapeutic substances are of great interest, especially drug delivery for cancer therapy includes boron-neutron capture therapy. The results of boron-rich compound (carborane borate) attachment to previously aminated by (3-aminopropyl)-trimethoxysilane iron oxide nanoparticles are presented. Energy-dispersive X-ray analysis and Fourier transform infrared spectroscopy with attenuated total reflection (ATR) accessory confirmed change of nanoparticles elemental content after modification and formation of new bond between Fe3O4 and attached molecules. Scanning and transmission electron microscopy showed that Fe3O4 nanoparticles average size is 18.9 nm. Phase parameters were investigated by powder X-ray diffraction, Fe3O4 nanoparticles magnetic behavior was evaluated by Mössbauer spectroscopy. Chemical and colloidal stability was studied using simulated body fluid (phosphate buffer – PBS). Modified nanoparticles have excellent stability in PBS (pH = 7.4), characterized by X-ray diffraction, Mössbauer spectroscopy and dynamic light scattering. Fe3O4 biocompatibility was elucidated in-vitro using cultured mouse embryonic fibroblasts. The obtained results show the increasing of IC50 from 0.110 mg/ml for Fe3O4 to 0.405 mg/ml for Fe3O4-Carborane nanoparticles. Obtained data confirm biocompatibility and stability of synthesized nanoparticles and potential to use them in boron-neutron capture therapy

Magnetic Properties of the Densely Packed Ultra-Long Ni Nanowires Encapsulated in Alumina Membrane

High-quality and compact arrays of Ni nanowires with a high ratio (up to 700) were obtained by DC electrochemical deposition into porous anodic alumina membranes with a distance between pores equal to 105 nm. The nanowire arrays were examined using scanning electron microscopy, X-ray diffraction analysis and vibration magnetometry at 300 K and 4.2 K. Microscopic and X-ray diffraction results showed that Ni nanowires are homogeneous, with smooth walls and mostly single-crystalline materials with a 220-oriented growth direction. The magnetic properties of the samples (coercivity and squareness) depend more on the length of the nanowires and the packing factor (the volume fraction of the nanowires in the membrane). It is shown that the dipolar interaction changes the demagnetizing field during a reversal magnetization of the Ni nanowires, and the general effective field of magnetostatic uniaxial shape anisotropy. The effect of magnetostatic interaction between ultra-long nanowires (with an aspect ratio of >500) in samples with a packing factor of ≥37% leads to a reversal magnetization state, in which a “curling”-type model of nanowire behavior is realized

A Study of Ta2O5 Nanopillars with Ni Tips Prepared by Porous Anodic Alumina Through-Mask Anodization

The paper discusses the formation of Ta2O5 pillars with Ni tips during thin porous anodic alumina through-mask anodization on Si/SiO2 substrates. The tantalum nanopillars were formed through porous masks in electrolytes of phosphoric and oxalic acid. The Ni tips on the Ta2O5 pillars were formed via vacuum evaporation through the porous mask. The morphology, structure, and magnetic properties at 4.2 and 300 K of the Ta2O5 nanopillars with Ni tips have been studied using scanning electron microscopy, X-ray diffraction, and vibrating sample magnetometry. The main mechanism of the formation of the Ta2O5 pillars during through-mask anodization was revealed. The superparamagnetic behavior of the magnetic hysteresis loop of the Ta2O5 nanopillars with Ni tips was observed. Such nanostructures can be used to develop novel functional nanomaterials for magnetic, electronic, biomedical, and optical nano-scale devices