Tantalum pentoxide, Ta2O5, is a high-index, low-absorption material usable for coatings in the near-UV (350 nm) to IR (>8 µm) regions. Dense, hard layers can be deposited by electron-beam evaporation or by sputtering. Typical applications include near-UV to near-IR antireflection and multilayer filter coatings. Tantala can be used in combination with low-index Silicon dioxide layers to form high index-contrast multilayer structures ranging from wide-band AR coatings to bandpass filters and dichroic beam-splitters. That material combination is used to make thick multi-layer stacks that exhibit very low stress. An advantage over Titanium dioxide layers is the absence of absorption above 900 nm, making Tantala a superior material for near-IR laser and bandpass coatings such as Nd:YAG laser and telecom applications. Hard, scratch-resistant and adherent coatings can be deposited on glass and metal substrates. Films are also used for dielectrics in film capacitors and as gate insulators in large scale integrated circuits requiring low leakage voltage characteristics.Information provided by Materion. |