tantalumoxid

Tantalumoxid, in English commonly called tantalum oxide, is a chemical compound of tantalum and oxygen. The most relevant oxide is Ta2O5, though tantalum can form other oxides with different stoichiometries. Ta2O5 is a white to pale yellow powder that is chemically very stable and has a high melting point.

Ta2O5 exhibits notable physical and chemical properties. It is highly resistant to corrosion, insoluble in water, and only slowly attacked by most acids; it can be dissolved in hot concentrated hydrofluoric acid to form soluble tantalate species. It has a high refractive index and is used as a dielectric material in thin films. In the context of microelectronics, Ta2O5 serves as a high-k dielectric layer in capacitors and as a gate dielectric in certain transistors. The material also forms several polymorphs that can transform with temperature, with different densities and dielectric characteristics.

Production and processing methods include the oxidation of tantalum metal to form surface Ta2O5, as well as chemical routes such as hydrolysis of tantalum compounds. Ta2O5 films can be deposited by chemical vapor deposition, atomic layer deposition, or sputtering and subsequently annealed to achieve desired crystal phases and properties. Doping and composite formation with other oxides are used to tailor dielectric and optical performance.

Applications of tantalumoxid are broad. In electronics, Ta2O5 is used for high-performance capacitors and as a dielectric layer in integrated circuits. In optics, the material’s high refractive index makes Ta2O5 suitable for anti-reflective coatings and optical waveguides. Due to its chemical stability and high-temperature behavior, tantalum oxide is also used in ceramic and coating technologies where durable, heat-resistant oxide layers are advantageous.