What is magnetron sputtering technology?
Magnetron sputtering is another form of PVD coating technology.
Magnetron sputtering is a plasma coating process whereby sputtering material is ejected due to bombardment of ions to the target surface. The vacuum chamber of the PVD coating machine is filled with an inert gas, such as argon. By applying a high voltage, a glow discharge is created, resulting in acceleration of ions to the target surface and a plasma coating. The argon-ions will eject sputtering materials from the target surface (sputtering), resulting in a sputtered coating layer on the products in front of the target.
Often an additional gas such as nitrogen or acetylene is used, which will react with the ejected material (reactive sputtering). A wide range of sputtered coatings is achievable with this PVD coating technique. Magnetron sputtering technology is very advantageous for decorative coatings (e.g. Ti, Cr, Zr and Carbon Nitrides), because of its smooth nature. The same advantage makes magnetron sputtering widely used for tribological coating in automotive markets (e.g. CrN, Cr2N and various combinations with DLC coating - Diamond Like Carbon coating).
Magnetron sputtering is somewhat different from general sputtering technology. The difference is that magnetron sputtering technology uses magnetic fields to keep the plasma in front of the target, intensifying the bombardment of ions. A highly dense plasma is the result of this PVD coating technology.
Magnetron sputtering technology is characterized by:
- A water-cooled target, so little radiation heat is generated
- Almost any metallic target material can be sputtered without decomposition
- Non-conductive materials can be sputtered by using radio frequency (RF)
or medium frequency (MF) power
- Oxide coatings can be sputtered (reactive sputtering)
- Excellent layer uniformity
- Very smooth sputtered coatings (no droplets)
- Cathodes (of up to 2 meter long) can be put in any position, therefore high
flexibility of sputtering equipment design
Magnetron sputtering technology has some disadvantages:
- Slow deposition speed compared to arc technology
- Lower plasma density (~5%) compared to arc technology; adhesion of coatings is
lower and density of the sputtered layers may be lower