Definition - What does Magnetron Sputtering mean?
Magnetron sputtering is a physical vapor deposition coating technique used to deposit thin films of materials, such as metals, plastics and ceramics, onto other surfaces or substrates.
The process is carried out in a vacuum or low-pressure environment where a magnetic field is used to concentrate high-energy ions onto the coating material in order to eject the atoms. Magnetron sputtering is widely used in scientific and commercial applications such as improving the corrosion resistance properties of steel and magnesium alloys.
Corrosionpedia explains Magnetron Sputtering
Magnetron sputtering is a powerful, flexible and material-independent coating process which can be used to coat most of common surfaces with a variety of materials. The high-energy atoms can penetrate into the substrate to create uniform and tight patterns that improve durability and performance of the surface.
The technique is widely used in commercial, industrial, scientific, and research industries. Typical coatings include:
- Wear-resistant coatings
- Low-friction coatings
- Decorative coatings
- Corrosion-resistant coatings
- Coatings with specific optical or electrical properties
- Medical coatings
- Other functional coatings
Typical applications include:
- Architectural glass
- Photovoltaic materials
- Superconductor materials
- Magnesium alloys for automotive and aerospace industries
Electrical energy is used to create high-energy plasma ions in a vacuum. A magnetron provides a magnetic field that concentrates the ions onto the target (cathode). As the ions strike the target, neutral atoms, molecules and secondary electrons are emitted (sputtering). The ejected atoms move toward the substrate where they condense to form a thin film of the coating material. The secondary electrons collide with the inert gas in the chamber and help to maintain the plasma.
The plasma, in the conventional magnetron sputtering method, is concentrated above the target and might cause ions to bombard and affect the corresponding film on the substrate. This is eliminated in the unbalanced magnetron sputtering method, where the magnetic field is arranged in a way to spread the plasma. This helps to maintain a low ion concentration near the substrate.