Chapter 3 - Surface Preparation for Film and Coating Deposition Processes

Abstract

Surface modification can include surface treatments such as roughening or smoothing the surface, making a harder surface by plasma treatment, or by activating a polymer surface by plasma treatment. Surface preparation includes surface treatments (surface modification) to change the properties of the surface in a desirable way as well as cleaning, which is the reduction of surface contamination to an acceptable level. One objective of any surface preparation procedure is to produce as homogeneous a surface as possible. Reproducible surface preparation, as well as the associated handling and storage techniques, is obtained by having and following appropriate written specifications and procedures. In order to have reproducible surface preparation processes it is generally necessary to have a reproducible and homogeneous starting surface. Cleaning is used so that desirable processing and film/coating properties can be obtained. External cleaning takes place outside the deposition system as a separate process in a controlled environment. It includes gross cleaning to remove large amounts of contaminants often by removing some of the substrate surface, and specific cleaning, which is directed toward removing a specific contaminant such as particulates, or hydrocarbons. A clean processing environment, and proper handling and storage after the external cleaning is important to minimize recontamination of the cleaned surface before it is placed in the deposition chamber. The objective of cleaning processes is to facilitate the fabrication of an acceptable product in the most reproducible and economical way.