Chapter 11 - Substrate Preparation

Abstract

It is unusual to utilize thin films as free-floating films. All thin films are formed by the deposition of atoms onto a substrate. Hence, the thin films and the substrate should be viewed collectively as a system in evaluating the properties. The substrate cleanliness is dependent on the pre-deposition processing steps. The substrate preparation techniques are carried out outside the deposition process. For preparation of high-quality surfaces, in situ preparation techniques prior to the deposition operation inside the deposition chamber appear to be essential. In order for cleaning to be successful, it is imperative that the various parts of the vacuum chamber, pieces of equipment should also be cleaned with a high degree of attention. A contaminant is any material on the surface of the substrate that has an influence on the formation of the film, properties of the film or the stability of the film. Contaminants, which are chemically bound to the surface, require heating of the sample when they may be removed as a volatile oxide, sulphide, or carbide or dissolve into the solid. The modification of the physical and mechanical properties of the surface is necessary for some applications.