Ion Beam Sputtering (IBS) or Ion Beam Deposition (IBD) is a Physical Vapour Deposition (PVD) technique when the layer of a desired material is formed by molecules extracted from the target material by a highly energetic and precisely controlled ion beam. An optical interference coating is created by stacking layers of different materials and precisely controlling the thickness of each layer. Coatings produced by the Ion Beam Sputtering method are proven to meet the most demanding industry and scientific requirements and provide numerous benefits for laser and laser systems manufacturers.
Inherently stable sputtering process
The principal difference between the sputtering process and evaporation is the mechanism of extracting molecules from the target material. The possibility of material sputtering is very much enabled by ion grid optics that can precisely control ion energy and beam focus. When the proper energy of ions is chosen in order to minimize ion implantation (typically 1000-2000eV) and they are precisely directed to the target material, desired atoms or molecules are knocked out from their stable positions by multiple collisions and can leave the target. Such interaction between ion beam and the target is called sputtering. Electrons, produced by RF neutraliser and directed to the ion beam, serve a dual purpose: 1) prevent spreading of the beam due to the repulsion among ions; 2) prevent electrical discharges in the chamber by neutralising overall beam charge. Since the ion gun is isolated as a separate device in the chamber, ion beam energy and ion density are very well controlled parameters. A very stable ion beam combined with high vacuum (~1x10-4 mbar during the deposition) and ultra-high purity metal targets (>99.99%) result in a super stable deposition process. It enables a fully automatic deposition and the ability to precisely control refractive indices and thicknesses of each deposited layer.