Element Six, a subsidiary of the mining giant De Beers, says that it is ready to respond to a sharp increase in demand for diamond optics in the coming months, as extreme ultraviolet (EUV) lithography tools move towards commercial production.

The company, which produces synthetic diamonds at its facility in Santa Clara, California, told optics.org at the recent SPIE Photonics West event that its diamond optical windows – claimed to be the largest ever produced – would help to “change the economics” of EUV lithography.

Because the EUV source in the tools being developed by ASML is created using a hugely powerful carbon dioxide laser (around 40 kW) aimed at tiny droplets of tin inside a vacuum chamber, the optical windows used in the source require some extraordinary properties.

That is exactly what diamond, with its extremely thermal conductivity, shock resistance and broadband optical transmission, offers, although it is very difficult to manufacture at the kind of sizes needed for the lithography application.

Having recently expanded its chemical vapor deposition (CVD) manufacturing capacity by 50% in Santa Clara, Element Six says it now has four-times the production scale of any of its rivals. “Diamond will not be the bottleneck,” said Henk de Wit, the firm’s business manager for optical applications.