Inverted cylindrical magnetron sputtering, or ICM sputtering, is a thin film deposition technique that coats films with excellent uniformity, regardless of the substrate’s geometry. ICM sputtering follows the same process steps as conventional magnetron sputtering. When positively charged ions from a generated plasma collide with a negatively biased target, atoms are ejected or sputtered onto the substrate to create a thin film.
A typical magnetron sputtering configuration uses planar cathodes, while ICM sputtering uses a cylindrical cathode. The substrate sits inside the cylinder, and instead of sputtering up or down, the cylindrical cathode sputters inwards toward the substrate. This geometry enables a high degree of uniformity on 3D or curved substrates, without sacrificing deposition rate or adding process steps for rotation.
Inverted cylindrical magnetron sputtering is a great option for applications that require uniform coatings on curved, 3D or complex substrates. ICM sputtering offers the repeatability needed for precision optics and delivers a more streamlined process for coating lens and other curved surfaces. Typically, you need to add rotation or planetary movement to make sure all sides are coated, but this slows down the process and makes for a complicated coating process. By sputtering the entire surface at once, ICM sputtering reduces complexity while achieving tighter uniformity and control.
Along with precision optics, ICM sputtering also offers very high thickness uniformity for medical device coatings, such as implants. Reliability is critical for these applications in order to protect patient safety. ICM sputtering is a good solution for achieving tight coating specs and can also help increase radiopacity of a device.
With inherently high deposition rates, ICM sputtering ensures you don’t have to sacrifice production volume and ROI to achieve high performance. This sputtering configuration can help lower cost of ownership as well, particularly in applications requiring expensive target materials. An inverted cylindrical cathode delivers highly uniform erosion across the surface of the target, improving target utilization for the entire system.