DC magnetron sputtering is one of several types of sputtering, which is a method of physical vapor deposition of thin films of one material onto another material. The most common sputter deposition methods in use in 2011 are ion beam sputtering, diode sputtering and DC magnetron sputtering. Sputtering has a wide variety of scientific and industrial uses, and is one of the fastest growing production processes used in modern manufacturing.
Very simply, sputtering occurs in a vacuum chamber, where a substance is bombarded with ionized gas molecules that displace atoms from the substance. These atoms fly off and hit a target material, called a substrate, and bond to it at an atomic level, creating a very thin film. This sputter deposition is done at an atomic level, so the film and the substrate have a virtually unbreakable bond and the process produces a film that is uniform, extremely thin and cost effective.
Magnetrons are used in the sputtering process to help control the path of the displaced atoms that fly randomly around the vacuum chamber. The chamber is filled with a low-pressure gas, frequently argon, and several high-voltage magnetron cathodes are placed behind the coating material target. High voltage flows from the magnetrons across the gas and creates high-energy plasma that strikes the coating material target. The force generated by these plasma ion strikes causes atoms to eject from the coating material and bond with the substrate.
The atoms that are ejected in the sputtering process usually fly through the chamber in random patterns. Magnetrons produce high-energy magnetic fields that can be positioned and manipulated to collect and contain the generated plasma around the substrate. This forces the ejected atoms to travel predictable paths to the substrate. By controlling the path of the atoms, the film deposition rate and thickness can also be predicted and controlled.
Using DC magnetron sputtering allows engineers and scientists to calculate times and processes needed to produce specific film qualities. This is called process control, and it allows this technology to be used by industry in mass manufacturing operations. For instance, sputtering is used to create coatings for optical lenses used in items such as binoculars, telescopes and infrared and night-vision equipment. The computer industry uses CDs and DVDs that were manufactured using spluttering processes, and the semiconductor industry uses sputtering to coat many types of chips and wafers.
Modern high-efficiency insulated windows use glass that was coated using sputtering, and many hardware, toy and decorative items are manufactured using this process. Other industries that use sputtering include the aerospace, defense and automotive industries, the medical, energy, lighting and glass industries, and many others. Despite its already broad use, industry continues to find new uses for DC magnetron sputtering.