29 Aug 2019
Glass giant partners with lithography equipment firm to mass produce high-refractive-index material.
Austria’s EV Group (EVG), which specializes in wafer bonding and lithography equipment, has teamed up with the optical glass giant Schott to help scale production of large glass wafer material intended for new applications in augmented and virtual reality (AR/VR).
The two firms say that they will demonstrate the readiness of 300 mm (12 inch) nanoimprint lithography (NIL) for high-volume patterning of the high-refractive index (HRI) material at next week’s China International Optoelectronic Exposition (CIOE) event in Shenzhen.
The approach has been developed for manufacturing precision waveguides in up to 1.9 index material that will be used as light guides in the forthcoming generation AR, VR, and “mixed reality” (MR) headsets.
Economies of scale
EVG says that the partnership combines its proprietary “SmartNIL” process with Schott’s “RealView” HRI glass wafer technology, the latest version of which was launched earlier this year at the Display Week exhibition in San Jose, California.
Schott is set to showcase one of the patterned wafers at the Shenzhen event, with its head of AR Rüdiger Sprengard saying in a company release:
“Scaling up to 300-mm manufacturing of high-refractive index glass wafers is critical to achieving the production volumes at the economies of scale that our customers need to meet growing market demand for today’s and tomorrow’s leading AR/MR devices.
“Through this joint effort, EVG and Schott are demonstrating the equipment and supply-chain readiness for 300-mm HRI glass manufacturing today.”
EVG explains that, until now, use of the NIL technique to pattern glass substrates with structures for photonics applications has been limited to 200 mm-diameter glass. The migration to the larger format - the same size of material used to make most silicon semiconductor chips - is seen as a key step for bringing new AR/VR/MR headsets into mass consumer and industrial markets at an affordable cost.
The Austrian equipment firm adds that a key challenge with that migration was maintaining high substrate quality and process uniformity on the larger substrates, which demands advanced automation and process control capabilities.
Its SmartNIL approach is said to address the nanopatterning requirements, with its new “HERCULES NIL 300 mm” machine bringing the technology to the larger wafer format.
Markus Wimplinger, director of corporate technology development at EVG, said in a separate release that the partnership with Schott was an example of progress made at its open access innovation incubator.
The incubator has been set up to allow a diverse set of partners and companies across the NIL supply chain to collaborate with EVG, with the aim of shortening development cycles and time-to-market for innovative photonic devices and applications.
“We are excited to partner with companies like Schott to demonstrate the value of EVG’s NIL solutions in not only enabling the development of new technologies and processes, but also accelerating their introduction to mass markets,” Wimplinger said.
“This current work proves the maturity of NIL equipment and processes, and is laying the groundwork for 300 mm manufacturing for a variety of exciting new photonics-based products and applications.”
The high refractive index of the latest Schott wafers is said to enable “deeply immersive” AR/VR/MR applications thanks to a wide diagonal field of view of up to 65 degrees – said to be far superior than any competing material currently on sale.
Having introduced the first generation of the material at last year’s Display Week event, Schott adds that it is already providing samples of the 300 mm-diameter glass to customers, and is ready to ramp up production as and when it is required.