Rapid Thermal Annealing applied to coatings on architectural glass: a breakthrough inspiring a full range of new highly-efficient functional coated glass products.

Starting from early eighties, the glass industry introduced the magnetron sputtering as a key-technology to functionalize large area glass (thermal insulation, solar reflection etc.). Contrarily to float CVD, PVD provokes limited thermal transfer to the films, leading to poorly-crystallized material. Later, new stack designs allowed the coated glass to be tempered. It improves significantly the crystallization of metallic or dielectric films but remains limited to glazings for which safety is required. Finally, Rapid Thermal Annealing (RTA) is a well-known batched technology developed for solid-phase recrystallization but was not so far applicable to architectural glass.

A unique proprietary-owned cost-effective technology has been developed to allow efficient RTA for architectural glass, fully integrated in the coater workflow without productivity degradation. The resistivity of silver films can be decreased up to 30%. In a similar way, the resistivity of TCOs (ITO) can be reduced up to 160 µOhm.cm, close to deposition on heated substrate. Finally, anatase crystallites can be detected on sputtered TiO2 films without any substantial glass heating.

This technology opens a large field to new cost-effective glass products with improved energetic balance, high transparency, improved electronic transport properties and many others. Alternative potential applications on polymer substrates will also be discussed.