Glossary of Terms

Here is a list of some of the technical terms commonly used when discussing CVD diamond thin films

  • Chemical Vapour Deposition (CVD): A gas phase chemical reaction which causes deposition of a solid material onto a nearby surface. In our case, it's diamond being deposited from a gas mixture containing a volatile carbon compound (such as methane, CO, etc) onto a hot substrate.
  • Homo-epitaxy: growth of one material on a substrate made of the same material. For example, growth of a thin film of diamond onto a single-crystal diamond surface. Homo-epitaxy is often truly epitaxial, i.e. the film lattice and the substrate lattice coincide and the boundary between the two is indiscernible.
  • Hetero-epitaxy: growth of one material on a substrate made of a different material. For example, a thin diamond film grown on a silicon substrate.

    • Types of Films

  • CVD Diamond Film: A film containing a high proportion of diamond crystallites of varying sizes and orientations, joined together with grain boundaries which may contain non-diamond material (e.g. graphitic carbon). The size and number of the crystallites is often used to describe the type of film:
  • Diamond-like Carbon (DLC): Films prepared by a number of mainly 'physical' methods, including direct plasma deposition, ion beam sputtering, plasma sputtering, etc. These films are a mixture of graphitic areas and diamond-areas, and have a variety of properties in between those of graphite and diamond. They can also be known as amorphous carbon (a-C) films, or ion-deposited films (i-C). They can also contain upto a few tens of % of hydrogen.
  • Amorphic or Amorphous Diamond Films: A variety of DLC which contain no hydrogen and are composed solely of carbon, again, in a mixture of graphitic and diamondlike forms.