Contamination in a vacuum system affects the environment in which vacuum processes are conducted. Understanding and controlling these contaminants are important steps in producing the desired chamber conditions that result in high-quality and reproducible products. This course discusses typical in-chamber contamination including gases, films, and particulates. The origin of these contaminants, typical effects that these contaminants have on vacuum processes and products, and methods of limiting them are discussed. Emphasis is on defining how to control each contaminant, and identifying appropriate procedures to confirm that the established contamination control is effective. There will also be discussion on the how contamination control may be related to the vacuum system operating and maintenance procedures, as well as the environment outside the chamber.

This course is intended to offer practical advice for operators, engineers, maintenance personnel, and vacuum system/process designers. It highlights Best Practices for operating complex vacuum systems for processes requiring low contamination and high reproducibility, e.g., guidance that would have been acquired historically through mentoring by experienced colleagues.

1. Defining the Vacuum Environment: This section describes how contamination is defined and quantified. This includes both particle and vaporous contamination, in both volumes and on surfaces. It also presents the history and structure of various contamination Standards, including those related to ISO-14611 for contamination in volumes (Previously U.S. Federal Standard 209), and IEST Standard CC1246 (Previously U.S. Military Standard 1246).
2. Pumping and Related Contamination: This section reviews the types of contamination that can be expected from typical pumps used in various types of vacuum technology. These pumps include wet and dry mechanical pumps, wet and dry high-vacuum pumps, and ultra-high vacuum pumps. Related discussion also included typical procedures and/or ancillary equipment that is often used to limit contamination from these various pumps.
3. Evacuating, Venting, and Condensation: This section reviews how the specific procedures used for venting, working within, and ultimately evacuating the chamber can have a profound effect on the type and amount of contamination potentially present during a vacuum process.
4. Mechanisms, Motors, Screws, and Bearings: This section reviews how the choice, preparation, location, and operation of typical vacuum-system components can result in various types of contamination. Components discussed include large components such as valves and mechanisms that impart movement to samples/products within the chamber, as well as much smaller components such as nuts, bolts, and pins used to fasten components.
5. Machining and Component Fabrication: This section describes how machining, welding, and post-fabrication procedures of the vacuum chamber and/or components can have a significant effect on in-chamber contamination. Procedures to limit fabrication-related contamination of various typical vacuum materials arepresented.
6. Process-Related Contamination: This section briefly reviews how most vacuum process produce contamination beyond those sources already discussed. Contamination related the leak detection, PVD sources, and source outgassing are provided as examples.
7. Lubrication-Related Contamination: This section briefly reviews how necessary low-friction “lubrication” can be provided within a vacuum chamber while still limiting contamination. The section reviews low-vapor-pressure fluid, grease, and solid-phase lubricants.
8. Vacuum System/Component Cleaning and The Clean-Room Environment: This section reviews some typical cleaning procedures used for vacuum chambers and components so that the vacuum environment produces minimal contamination. Similar typical cleaning procedures used for products/samples is also presented. The section concludes with a discussion of the design of clean room environments, and how these are typically designed for effective use and maintenance of vacuum-process equipment.