Author: Jung Won Cho
Publisher:
ISBN:
Category :
Languages : en
Pages : 227

Get Book Here

Book Description
Keywords: plasma diagnostics, thermal conductivity, AlN, pulsed DC sputtering.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :

Get Book Here

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.

Author: Al-Ahsan Talukder
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 0

Get Book Here

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.

Author: Mark A. Prelas
Publisher: Springer Science & Business Media
ISBN: 9401155925
Category : Technology & Engineering
Languages : en
Pages : 378

Get Book Here

Book Description
Diamond-based composites, with their advantages of hardness, high Young's modulus and the like, have demonstrated new and unusual features, such as stability to high temperatures and pressure shocks and a large internal surface that can be controlled to offer customised electrical, magnetic and optical properties, leading to efficient filters, absorbents, sensors and other tools for environmental control and monitoring. The current book covers the synthesis of materials, their characterization and properties, trends in high pressure and high temperature technologies, low pressure technologies, basic principles of DBC material science, and future developments in electronics, optics, industrial tools and components, biotechnology, and medicine. Wide band-gap materials are considered, ranging from molecular clusters, nanophase materials, growth, processing and synthesis. The processing of composite based materials can be classified into six basic methods: in situ growth, high pressure/high temperature catalytic conversion; mix and sinter (c-BN plus metal-ceramic polymer mix); direct sintering; direct polymorphic conversion; shock detonation; and SHS sintering.

Author: Alvin G. Randolph
Publisher:
ISBN:
Category : Aluminum nitride
Languages : en
Pages : 160

Get Book Here

Book Description
"Aluminum nitride thin films ( -1000 A) have been deposited on silicon substrate by re active sputtering using Al target in 1 : 1 Ar:N2 environment. The atomic force microscopy examination revealed continuous microcrystalline film structure. The Auger electron spectroscopic analysis shows the presence of oxygen in the films. The annealing at 850 C in nitrogen is found to cause recrystallinization and, by FTIR analysis, further oxidation of the films. The films can be characterized as lossy dielectrics with relative permittivity ~ 10, higher than the bulk value of 8.9. Annealing the films is found to reduce anion vacancies and improve the dielectric strength within a range of a few MV/cm in these thin films. Optical constants, n & k, have been obtained from reflectance and transmittance spec tra (190-900 nm) of films on fused silica. The results indicate the presence of a low energy absorption tail, and exponential absorption that is proportional to degree of disorder in the film. The average defect density of the film as deposited was 1.1 x 10^20 cm"3. Annealing the film at 760 C increased the degree of disorder resulting in an average defect density of 3.4 x 10^20 cm^-3. Subsequent annealing at 800 C and 850 C systematically decreased the degree of disorder and the average defect density. The real part of permittivity (e1) of the annealed films over this frequency range varies approximately +-0.5 from the e(infinity) of 4.84"--Abstract.

Author: Elizabeth Holm
Publisher: Springer
ISBN: 3319487701
Category : Technology & Engineering
Languages : en
Pages : 315

Get Book Here

Book Description
This collection represents a cross-section of the papers presented at the 6th International Conference on Recrystallization and Grain Growth. The volume is divided into nine sections: • Grain growth theory and simulation • Recrystallization theory and simulation • Low carbon and IF steels • High strength steels • Electrical steels • Stainless steels • Aluminum and magnesium alloys • Nickel and nickel based superalloys • Unconventional and advanced materials

Author: Mohd Adreen Shah Azman Shah
Publisher:
ISBN:
Category : Aluminum nitride
Languages : en
Pages : 108

Get Book Here

Book Description

Author: Nathaniel Mark Williams
Publisher:
ISBN:
Category : Dielectric films
Languages : en
Pages : 296

Get Book Here

Book Description

Author: William A. Carrington
Publisher:
ISBN:
Category :
Languages : en
Pages : 146

Get Book Here

Book Description

Author: Filipe Vaz
Publisher: Bentham Science Publishers
ISBN: 1608051560
Category : Technology & Engineering
Languages : en
Pages : 363

Get Book Here

Book Description
Oxynitride thin film technology is rapidly impacting a broad spectrum of applications, ranging from decorative functions (through optoelectronics) to corrosion resistance. Developing a better understanding of the relationships between deposition processes, structure and composition of the deposited films is critical to the continued evolution of these applications. This e-book provides valuable information about the process modeling, fabrication and characterization of metallic oxynitride-based thin films produced by reactive sputtering and some related deposition processes. Its contents are spread in twelve main and concise chapters through which the book thoroughly reviews the bases of oxynitride thin film technology and deposition processes, sputtering processes and the resulting behaviors of these oxynitride thin films. More importantly, the solutions for the growth of oxynitride technology are given in detail with an emphasis on some particular compounds. This is a valuable resource for academic learners studying materials science and industrial coaters, who are concerned not only about fundamental aspects of oxynitride synthesis, but also by their innate material characteristics.