AVS 51st International Symposium
    Thin Films Wednesday Sessions
       Session TF-WeM

Paper TF-WeM7
Spectrally Stable Optical Coatings Using Closed Field Reactive Magnetron Sputtering

Wednesday, November 17, 2004, 10:20 am, Room 303C

Session: Optical Thin Films
Presenter: J.M. Walls, Applied Multilayers Ltd, UK
Authors: J.M. Walls, Applied Multilayers Ltd, UK
D.G. Gibson, Applied Multilayers Ltd, UK
Correspondent: Click to Email
Magnetron Sputtering has many advantages for the deposition of multilayer optical coatings. The sputtering process is "cold", making it suitable for use on the widest range of substrates including polymers. This paper will describe the "Closed Field" process that allows high quality, multilayer metal-oxide thin films to be deposited at high rates with exceptionally low absorption. In contrast to previous reactive dc sputtering strategies the Closed Field process does not require a separate ion or plasma source. The Closed Field creates a magnetic bottle that extends the electron mean free path leading to high ion current densities. The combination of high current densities with ion energies in the range 30eV to 50eV creates optimum thin film growth conditions. As a result the films are dense and spectrally stable. Also, they are exceptionally smooth as measured using FEGSEM and Coherence Correlation Interferometry Examples of the morphology and optical properties of single layer electrically insulating (SiO2, Nb2O5 and TiO2) and conducting meat oxides (ITO) will be presented. The structure and morphology of a series of multi-layer metal oxide coatings will also be presented These will include ant-reflective coatings, UV and infra-red blockers, lighting filters and conductive oxides for flat screen displays.