A Study Of The Composition Structure And Properties Of Amorphous Hydrogenated Diamond Like Carbon Films

Amorphous, hydrogenated carbon (AHC) films can be deposited on various substrates using several techniques, e.g. plasma deposition and ion beam deposition. The resulting films can be hard, wear resistant and transparent.

This book highlights some of the most important structural, chemical, mechanical and tribological characteristics of DLC films. It is particularly dedicated to the fundamental tribological issues that impact the performance and durability of these coatings. The book provides reliable and up-to-date information on available industrial DLC coatings and includes clear definitions and descriptions of various DLC films and their properties.

Diamond-like carbon coatings produced by Plasma Source Ion Implantation (PSII) and beamline Ion Beam Assisted Deposition (IBAD) were synthesized and studied. Gas pressure and electrical current were used as variables to design four independent PSII test sets. Beamline IBAD samples were produced with a pre-optimized set of parameters. Profilometry measurements showed the films to have thicknesses between 1.44 +/- 09 and 1.64 +/- 04 microns and to possess very low roughness averages, ranging from 14 +/- 3 to 28 +/- 3 nm, which correlate with substrate surface roughness. Atomic Force Microscopy revealed that diamond-like carbon crystal sizes varied significantly with chamber pressure. Crystals were generally spherical in shape suggesting that films were highly amorphous. Microhardness and nanohardness test results showed the hardest films to be greater than 3 times the hardness of untreated steel. The elastic modulus of the films, measured during the nanohardness test, was directly related to film hardness. Fretting wear and Pin-on-Disk tests were performed to quantitatively assess the ability of films to resist wear. Fretting wear tests showed a dramatic decrease in friction for diamond-like carbon films with friction levels ranging from 10% to 30% of that of untreated steel. Pin-on-Disk tests revealed a significant improvement in wear resistance prior to stylus penetration into the substrate.

World experts in amorphous carbon have been drawn together to produce this comprehensive commentary on the current state and future prospects of amorphous carbon, a highly functional material. Amorphous carbon has a wide range of properties that are primarily controlled by the different bond hybridisations possible in such materials. This allows for the growth of an extensive range of thin films that can be tailored for specific applications. Films can range from those with high transparency and which are hard and diamond-like, through to those which are opaque, soft and graphitic-like. Application areas including field emission cathodes, MEMs, electronic devices, medical and optical coatings are now close to market.

Results of the study of structural features and optical properties of thin films of amorphous hydrogenated carbon (a-C:H) films prepared by plasma-activated chemical vapor deposition of various hydrocarbon precursors are reviewed. The effect of different factors on the rate of a-C:H films deposition in a DC glow discharge with the magnetron plasma localized near the anode such as voltage, discharge power, gas pressure, relative content of an inert gas in the mixture with a hydrocarbon and other is analyzed. It is shown that the refractive index of a-C:H films can be changed in the interval 2.35-1.55 by increasing the deposition rate and the choice of the appropriate hydrocarbon precursor. The features of the vibration spectra of the diamond-like and polymer-like films are discussed. The correlations of the structural peculiarities and of the optical absorption edge, gap width, and conductivity as well as the absorption spectra in visible region and the ratio of the fundamental bands in Raman scattering spectra are estimated. Examples of using the optical properties of the a-C:H films are given.

This book is a compilation of research work in the interdisciplinary areas of electronics, communication, and computing. This book is specifically targeted at students, research scholars and academicians. The book covers the different approaches and techniques for specific applications, such as particle-swarm optimization, Otsu’s function and harmony search optimization algorithm, triple gate silicon on insulator (SOI)MOSFET, micro-Raman and Fourier Transform Infrared Spectroscopy (FTIR) analysis, high-k dielectric gate oxide, spectrum sensing in cognitive radio, microstrip antenna, Ground-penetrating radar (GPR) with conducting surfaces, and digital image forgery detection. The contents of the book will be useful to academic and professional researchers alike.

This book presents current research from across the globe in the study of diamond-like carbon films. Topics discussed include the peculiarities of ion-beam synthesis of carbon-based phases; electron field emission properties of non-metal and metal doped diamond like carbon; internal stress and its reduction of hydrogenated diamond-like carbon thin films deposited by plasma CVD methods; incorporating crystalline diamond particles in diamond-like carbon films to improve their properties and diamond-like carbon films applied as an alignment layer for LCDs.