An Investigation of Reactively Sputtered Thin Film Superconducting Nitrides PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download An Investigation of Reactively Sputtered Thin Film Superconducting Nitrides PDF full book. Access full book title An Investigation of Reactively Sputtered Thin Film Superconducting Nitrides by Herbert Harold Bell. Download full books in PDF and EPUB format.
Author: Herbert Harold Bell
Publisher:
ISBN:
Category : Superconductors
Languages : en
Pages : 142
Get Book Here
Book Description
Author: Herbert Harold Bell
Publisher:
ISBN:
Category : Superconductors
Languages : en
Pages : 142
Get Book Here
Book Description
Author: Tae Hoon Kim
Publisher:
ISBN:
Category : Sputtering (Physics)
Languages : en
Pages : 168
Get Book Here
Book Description
Author: Divyang Manharlal Shah
Publisher:
ISBN:
Category : Sputtering (Physics)
Languages : en
Pages : 160
Get Book Here
Book Description
Author: Tuomas Hänninen
Publisher: Linköping University Electronic Press
ISBN: 9176853748
Category :
Languages : en
Pages : 73
Get Book Here
Book Description
Silicon nitride and silicon nitride-based ceramics have several favorable material properties, such as high hardness and good wear resistance, which makes them important materials for the coating industry. This thesis focuses the synthesis of silicon nitride, silicon oxynitride, and silicon carbonitride thin films by reactive magnetron sputtering. The films were characterized based on their chemical composition, chemical bonding structure, and mechanical properties to link the growth conditions to the film properties. Silicon nitride films were synthesized by reactive high power impulse magnetron sputtering (HiPIMS) from a Si target in Ar/N2 atmospheres, whereas silicon oxynitride films were grown by using nitrous oxide as the reactive gas. Silicon carbonitride was synthesized by two different methods. The first method was using acetylene (C2H2) in addition to N2 in a Si HiPIMS process and the other was co-sputtering of Si and C, using HiPIMS for Si and direct current magnetron sputtering (DCMS) for graphite targets in an Ar/N2 atmosphere. Langmuir probe measurements were carried out for the silicon nitride and silicon oxynitride processes and positive ion mass spectrometry for the silicon nitride processes to gain further understanding on the plasma conditions during film growth. The target current and voltage waveforms of the reactive HiPIMS processes were evaluated. The main deposition parameter affecting the nitrogen concentration of silicon nitride films was found to be the nitrogen content in the plasma. Films with nitrogen contents of 50 at.% were deposited at N2/Ar flow ratios of 0.3 and above. These films showed Si-N as the dominating component in Si 2p X-ray photoelectron spectroscopy (XPS) core level spectra and Si–Si bonds were absent. The substrate temperature and target power were found to affect the nitrogen content to a lower extent. The residual stress and hardness of the films were found to increase with the film nitrogen content. Another factors influencing the coating stress were the process pressure, negative substrate bias, substrate temperature, and HiPIMS pulse energy. Silicon nitride coatings with good adhesion and low levels of compressive residual stress were grown by using a pressure of 600 mPa, a substrate temperature below 200 °C, pulse energies below 2.5 Ws, and negative bias voltages up to 100 V. The elemental composition of silicon oxynitride films was shown to depend on the target power settings as well as on the nitrous oxide flow rate. Silicon oxide-like films were synthesized under poisoned target surface conditions, whereas films deposited in the transition regime between poisoned and metallic conditions showed higher nitrogen concentrations. The nitrogen content of the films deposited in the transition region was controlled by the applied gas flow rate. The applied target power did not affect the nitrogen concentration in the transition regime, while the oxygen content increased at decreasing target powers. The chemical composition of the films was shown to range from silicon-rich to effectively stoichiometric silicon oxynitrides, where no Si–Si contributions were found in the XPS Si 2p core level spectra. The film optical properties, namely the refractive index and extinction coefficient, were shown to depend on the film chemical bonding, with the stoichiometric films displaying optical properties falling between those of silicon oxide and silicon nitride. The properties of silicon carbonitride films were greatly influenced by the synthesis method. The films deposited by HiPIMS using acetylene as the carbon source showed silicon nitride-like mechanical properties, such as a hardness of ~ 20 GPa and compressive residual stresses of 1.7 – 1.9 GPa, up to film carbon contents of 30 at.%. At larger film carbon contents the films had increasingly amorphous carbon-like properties, such as densities below 2 g/cm3 and hardnesses below 10 GPa. The films with more than 30 at.% carbon also showed columnar morphologies in cross-sectional scanning electron microscopy, whereas films with lower carbon content showed dense morphologies. Due to the use of acetylene the carbonitride films contained hydrogen, up to ~ 15 at.%. The co-sputtered silicon carbonitride films showed a layered SiNx/CNx structure. The hardness of these films increased with the film carbon content, reaching a maximum of 18 GPa at a film carbon content of 12 at.%. Comparatively hard and low stressed films were grown by co-sputtering using a C target power of 1200 W for a C content around 12 at.%, a negative substrate bias less than 100 V, and a substrate temperature up to 340 °C.
Author: Gisela Hertel
Publisher:
ISBN:
Category :
Languages : en
Pages : 338
Get Book Here
Book Description
Author:
Publisher:
ISBN:
Category : Nuclear energy
Languages : en
Pages : 1146
Get Book Here
Book Description
Author: Louis Toth
Publisher: Elsevier
ISBN: 032315722X
Category : Technology & Engineering
Languages : en
Pages : 296
Get Book Here
Book Description
Refractory Materials, Volume 7: Transition Metal Carbides and Nitrides discusses the developments in transition metal carbide and nitride research. This volume is organized into nine chapters that emphasize the mechanical and superconducting properties of these compounds. The introductory chapters deal with the general properties, preparation techniques, characterization, crystal chemistry, phase relationships, and thermodynamics of transition metal carbides and nitrides. The following chapter highlights the mechanical properties of these compounds, such as elastic and plastic deformation, fracture, strengthening mechanisms, and hardness. The discussion then shifts to specific electrical and magnetic properties, including electrical resistivity, Hall coefficient, and magnetic susceptibility. A separate chapter is devoted to carbides and nitrides as superconductors. The concluding chapters explore certain theories that explain the mechanisms of band structure and bonding in carbides and nitrides. This volume is of great value to research workers in metallurgy, ceramics, physics, chemistry, and related fields, as well as to advanced students investigating problems concerning high temperature materials or interstitial compounds.
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Zirconium nitride (ZrN) thin films were deposited by reactive dc magnetron sputtering to assess the effects of processing conditions upon film properties. Processing conditions and parameters were optimized to generate films of completely oriented (111) ZrN on silicon to be used as buffer layers for the growth of gallium nitride A single and double Langmuir probe were used to determine trends in electron temperature, ion density, ionization fraction, and floating potential during reactive sputtering of zirconium in argon and nitrogen. Reactive gas concentration, deposition pressure, deposition temperature, cathode current, film thickness and substrate orientation were investigated as variable processing conditions. Four-point probe, scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy, and x-ray diffraction (XRD) were used to characterize thin films produced. The optimum growth conditions for the (111) oriented growth of ZrN, for this work, were found to occur during reactive magnetron sputtering at a deposition temperature of 500 & deg;C, a constant cathode current of 0.5 ampere, a deposition pressure of 15 mTorr, a reactive nitrogen gas concentration of 4% in argon, deposited on (111) oriented silicon, with a thickness on the order of 600 nanometers. Gallium nitride was then deposited on films of ZrN to assess the crystallinity of films produced. The lattice mismatch between (111) oriented ZrN and c-axis oriented GaN was calculated at 1.6%. Microscopic evaluation showed the films to be of columnar structure with dense grains and smooth surfaces. A change in preferred orientation was noticed as a function of increasing film thickness and cathode current and was determined to be due to an increase in ion channeling and bombardment energy.
Author: Yimin Wang
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Molybdenum nitride thin film was deposited on silicon wafer by the reactive sputter deposition. Single phase?6Mo 2 N thin film was obtained with N 2 /(Ar+N 2) flow ratios in sputtering gas varying from 10% to 30% whereas an amorphous structure was obtained at N2/(Ar+N2) flow ratios of 50%. The deposition rate of the molybdenum nitride thin film varies significantly as nitrogen partial pressure in sputtering gas increases. A decrease in peak intensity along with peak shift and broadening was observed in X-ray diffraction spectra as the nitrogen partial pressure sputtering gas increased. The XPS analysis of the as-deposited thin films shows that the Mo 3d 3/2, Mo 3d 5/2 and Mo 2p 3/2 peak gradually shift to the higher binding energy direction as nitrogen partial pressure is increasing. The intensity of N 1s peak also increase with increasing nitrogen partial pressure. Although the XRD examination shows no evidence of long range order of the phase structure for the amorphous thin film sputtered at 50% N 2 /(Ar+N 2) flow ratio, the existence of Mo6N bond in the film was confirmed by XPS examination. The nitrogen partial pressure in the sputtering gas was found to have significant influence on the surface morphologies and cross section structures of the thin film. Thermal annealing of the amorphous thin film in a nitrogen atmosphere revealed that the film could survive 700ʻC,5min thermal annealing without obvious crystallization but failed after 800ʻC,5min thermal annealing, in which the crystalline?-Mo 2 N and h6MoSi 2 phases were observed simultaneously.
Author: Lucy Elizabeth Archer
Publisher:
ISBN:
Category :
Languages : en
Pages : 78
Get Book Here
Book Description
In this thesis I made a study of the properties of reactively sputtered ultra-thin films of niobium nitride (NbN) and niobium titanium nitride (NbTiN). Using Variable Angle Spectral Ellipsometry (VASE), I found that the optical properties of NbN films appear to have a critical thickness above which the optical parameters stabilize. I also found that the deposition process has better stability over time for thicker films than for thinner ones; that is, when films are deposited weeks apart, the thinner films show more variation in thickness and optical properties than do the thicker films. The data also suggest that the crystallinity of the substrate upon which the NbN is deposited has a significant effect on the optical parameters. The set of films deposited for the optical study was also tested against a universal scaling law for thin film superconductors, which seems to support the existence of the critical thickness, below which the properties change significantly and do not conform to the power law scaling that holds for thicker films. Finally, I explored recipes for depositing NbTiN with our sputtering system, in the hope of creating films that have better properties than NbN to be used in device manufacturing. I was able to create films with the same properties as our current NbN films with minimal optimization, and further work in this area should result in NbTiN films that are better than our NbN films.
