Author: Moushab BenkahoulPublisher:
ISBN:
Category :
Languages : en
Pages : 82
Book Description
Niobium Nitride Based Thin Films Deposited by DC Reactive Magnetron Sputtering
Author: Moushab BenkahoulThe Ion-beam Reactive Sputtering Process for Deposition of Niobium Nitride Thin Films
Author: Daniel Jenner LichtenwalnerPublisher:
ISBN:
Category :
Languages : en
Pages : 658
Book Description
Optical Properties of Ultra-thin Niobium Nitride Films for Single Photon Detectors
Author: Lucy Elizabeth ArcherPublisher:
ISBN:
Category :
Languages : en
Pages : 78
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.
Superconducting Multilayer Technology for Josephson Devices : Technology, Engineering, Physics, Applications
Author: Meckbach, Johannes MaximilianPublisher: KIT Scientific Publishing
ISBN: 3731501228
Category : Science
Languages : en
Pages : 204
Book Description
Within this book fabrication processes for high-quality Josephson junctions based on niobium and aluminum oxide as well as niobium nitride and aluminum nitride on various substrates are discussed. Techniques for achieving a planar chip topography and sub-μm lateral dimensions, aiding the realization of sophisticated Josephson devices such as SQUIDs, flux-flow oscillators and long Josephson junctions with artificial phase discontinuities, are presented in detail.
Reactive Ion Enhanced Magnetron Sputtering of Nitride Thin Films
Author: Al-Ahsan TalukderPublisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0
Book Description
Magnetron sputtering is a popular vacuum plasma coating technique used for depositing metals, dielectrics, semiconductors, alloys, and compounds onto a wide range of substrates. In this work, we present two popular types of magnetron sputtering, i.e., pulsed DC and RF magnetron sputtering, for depositing piezoelectric aluminum nitride (AlN) thin films with high Young's modulus. The effects of important process parameters on the plasma I-V characteristics, deposition rate, and the properties of the deposited AlN films, are studied comprehensively. The effects of these process parameters on Young's modulus of the deposited films are also presented. Scanning electron microscope imaging revealed a c-axis oriented columnar growth of AlN. Performance of surface acoustic devices, utilizing the AlN films deposited by magnetron sputtering, are also presented, which confirms the differences in qualities and microstructures of the pulsed DC and RF sputtered films. The RF sputtered AlN films showed a denser microstructure with smaller grains and a smoother surface than the pulsed DC sputtered films. However, the deposition rate of RF sputtering is about half of the pulsed DC sputtering process. We also present a novel ion source enhanced pulsed DC magnetron sputtering for depositing high-quality nitrogen-doped zinc telluride (ZnTe:N) thin films. This ion source enhanced magnetron sputtering provides an increased deposition rate, efficient N-doping, and improved electrical, structural, and optical properties than the traditional magnetron sputtering. Ion source enhanced deposition leads to ZnTe:N films with smaller lattice spacing and wider X-ray diffraction peak, which indicates denser films with smaller crystallites embedded in an amorphous matrix.
Pulsed DC Reactive Magnetron Sputtering of Aluminum Nitride Thin Films
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Aluminum nitride thin films have been deposited by pulsed DC reactive magnetron sputtering. The pulsed DC power provides arc-free deposition of insulating films. Two types of pulsed DC (unipolar and asymmetric bipolar) were studied with respect to characteristics and properties of resultant films. The unipolar power supply generates a series of 75 kHz DC pulses modulated with 2.5 kHz frequency. The frequency of asymmetric power supply can be varied from 50 kHz to 250 kHz. The duty cycle, which is a ratio of negative pulse time to total time, can be varied from 60% to 98%. Very fast oscillation and overshoot were observed when the polarity of the target voltage was changed. The control of crystal orientation of deposited film is important since the properties of AlN film is related with the orientation. For example, the acoustic velocity is high along the c-axis. The electromechanical coupling coefficient is large in a-axis direction. The crystal orientation and microstructure of the AlN films were strongly affected by the deposition conditions such as sputtering power, growth temperature, sputtering gas pressure and frequency/duty cycle. The crystal orientation of AlN films was closely related with the energy of sputtered atoms and mobility of adatoms on substrate. The c-axis oriented films were obtained when the target power and growth temperature were high. This provided higher energy of sputtered atoms and mobility of adatoms. The deposited AlN films have a columnar structure. The crystal orientation of the AlN films was changed from (101) to (002) by applying an RF bias was applied to the substrate in unipolar pulsed DC sputtering. The columnar structure disappeared when the RF bias was applied to the substrate. Applying bias was thought to increase mobility of adatoms by ion bombardment. MIM (aluminum-AlN-aluminum or molybdenum) structure was fabricated to measure electric properties of AlN films. Dielectric constants of 8.5 to 11.5 were obtained at 100 kHz. Th.
Modified Reactive Sputter Deposition of Titanium Nitride Thin Films Via HiPIMS with Kick-pulse and Improvement of the Structure-zone Model
Author: Andrew J. MiceliPublisher:
ISBN:
Category : Magnetron sputtering -- Methodology -- Testing
Languages : en
Pages : 0
Book Description
Direct current (DC) and radio frequency (RF) sputtering methods have been commonplace in industry for several decades and widely studied in literature. Hard films of nitrides, such as titanium nitride (TiN), have been deposited using reactive DC sputtering onto cutting tools and medical devices extensively as well. For these applications, the films require excellent adhesion, high density, and high hardness. High-Power Impulse Magnetron Sputtering (HIPIMS) has emerged over the last several years as a method to produce films with increased density and mechanical properties. Process-structure-property relationships for reactive HIPIMS are not yet well developed. Additionally, conventional HIPIMS suffers from relatively low deposition rates, which becomes a challenge or barrier of adoption for applied TiN coatings that are typically greater than several microns in thickness. This work aims to look at increasing this deposition rate while maintaining the beneficial effects of HIPIMS by utilizing the short duration "kick-pulse" in the voltage/current cycle, leading to higher instantaneous deposition rates and increased adatom energy level. TiN films are deposited onto silicon (Si) wafers under varied reactive sputtering conditions, including DC, HIPIMS, and HIPIMS with kick-pulse. Structural characterizations are performed using scanning electron microscopy (SEM) and X-ray diffraction (XRD). Optical properties of the resulting films are also characterized using reflection UV-Vis spectroscopy. The deposition rate, morphology, and chemical composition of the films are highly affected by the processing conditions, with the kick-pulse producing significant increase in deposition rate and observed grain size. Further investigation will aim to develop a modified structural zone model to include HIPIMS with and without kick-pulse.
Chemical Abstracts
Author: Multicomponent Nitride Thin Films by Reactive Magnetron Sputtering
Author: Kristina JohanssonThe Development and Characterisation of Advanced Ternary Nitride Thin Films Deposited by Reactive D.C Magnetron Co-sputtering Technology
Author: Richard WuhrerPublisher:
ISBN:
Category : Magnetrons
Languages : en
Pages : 644
Book Description