AVS 49th International Symposium
    Thin Films Monday Sessions
       Session TF-MoM

Paper TF-MoM3
Hybrid Deposition of Sputtered and Evaporated Multilayer Thin Films

Monday, November 4, 2002, 9:00 am, Room C-101

Session: Optical Thin Films
Presenter: P.M. Martin, Pacific Northwest National Laboratory
Authors: P.M. Martin, Pacific Northwest National Laboratory
L. Olsen, Pacific Northwest National Laboratory
J.W. Johnston, Pacific Northwest National Laboratory
D.M. DePoy, Knolls Atomic Power Laboratory
Correspondent: Click to Email
Si:H/CaF@sub 2@ high reflectors with as many as 27 layers were deposited by a hybrid process that combined reactive magnetron sputtering and electron beam evaporation. The ultimate goal of this work was to deposit interference filters with low NIR and LWIR absorption for use in thermophotovoltaic systems. The high index Si:H layers were deposited by reactive magnetron sputtering in mixtures of Ar + H@sub 2@. Electron beam evaporation was the preferred deposition method for the CaF@sub 2@ layers.@footnote 1@ The multilayer hybrid coatings were deposited in the same chamber by sequentially rotating the substrate over the Si sputtering target and the CaF@sub 2@ evaporation source. The deposition rate of the evaporated CaF@sub 2@ was 600 Å/min, compared to 25 Å/min for sputtered CaF@sub 2@. The deposition rate of the Si:H layers was 56 Å /min. The optical performance of the hybrid deposited and fully sputter-deposited coatings will be compared. The refractive index of the SiH at NIR wavelengths was 3.25, with extinction coefficient < 0.001. The refractive index of the CaF@sub 2@ in the same wavelength range was 1.34, with an extinction coefficient < 0.0001. The resulting multilayer coatings had lower physisorbed water, lower optical absorption and lower mechanical stress than those with sputtered CaF@sub 2@ layers. Advantages of this hybrid deposition method were reduced deposition times, optimum deposition process for each layer material, and improved optical and mechanical properties. This deposition method could be used for any type of multilayer optical or non-optical coating design, including but not limited to high reflectors, notch filters, beam splitters, antireflection, edge filters, polarizers, Fabrey-Perot filters, tuned absorbers, heterojunction semiconductor devices, thin film photovoltaic devices, superlattice devices, and thermoelectric devices. @FootnoteText@@footnote 1@J. D. Traylor Kruschwitz and W. T. Pawlewicz, Appl. Opt. (1997), 36(10), 2157-2159.