Lithography plays a key role in the production of integrated circuits and now accounts for some 35% of the processing cost of silicon chips. It involves directing light through a photomask to project an image of the desired circuit onto the silicon semiconductor wafer covered with a light-resistant photoresist. As circuit details become smaller and smaller, the wavelength of the light has also reduced and is reaching the limits of the deep ultraviolet range. The solution for future generations of even smaller dimensioned circuits is the use of EUV with a wavelength of 13.5 nm, which are actually considered as soft X-rays.
Covering the main elements of the lithography process
The projects focused on the main elements of the lithography process including tools, masks, illumination sources and processing. Extensive work was carried out on optics and coating technologies for project T403 EXTATIC which has led to the development of a full-field EUV lithographic research tool essential for future research – two tools are being delivered in 2006. Developing a complete mask-making process for 45 nm circuit structures and below was the aim in the T404 EXTUMASK project. First commercial masks have now been delivered to ASML – the Netherlands-based global leader in chipmaking lithography equipment. T405 EUV SOURCES focused on high power sources and achieved world record outputs, meaning power sources are no longer a blocking issue. Finally, the T406 EXITE project set out to eliminate the bottlenecks related to EUV imaging for full-field development.
"The EUV projects are achieving remarkable results and Europe is now at the leading edge of the technology globally," says Rob Hartman of ASML and chairman of the MEDEA+ EUV Cluster Steering Council (CSC). "It was working in cooperation within the framework of the EUREKA MEDEA+ Cluster that made this success possible."