Towards a magnetic field separation in Ion Beam Sputtering processes

•We use bent magnetic fields to guide and separate the sputtered deposition material.•No line of sight between substrate and target prevents thin films from particles.•The transport efficiency of binary and ternary oxides is investigated.•The defect statistics of manufactured dielectric ternary multilayers are evaluated.•The phase separation leads to a drastically reduction of particle contamination.

Defects embedded in coatings due to particle contamination are considered as a primary factor limiting the quality of optical coatings in Ion Beam Sputtering. An approach combining the conventional Ion Beam Sputtering process with a magnetic separator in order to remove these particles from film growth is presented. The separator provides a bent axial magnetic field that guides the material flux towards the substrate positioned at the exit of the separator. Since there is no line of sight between target and substrate, the separator prevents that the particles generated in the target area can reach the substrate. In this context, optical components were manufactured that reveal a particle density three times lower than optical components which were deposited using a conventional Ion Beam Sputtering process.