Manufacturing of the first EUV full-field scanner mask

In the framework of the European EXTUMASK project, the Advanced Mask Technology Center in Dresden (AMTC) has established in close collaboration with the Institute of Microelectronics in Stuttgart (IMS-Chips) an integrated mask process suited to manufacture EUV masks for the first full field EUV scanner, the ASML α-demo tool. The first product resulting from this process is the ASML set-up mask, an EUV mask designed to realize the tool set-up. The integrated process was developed based on dummy EUV blank material received from Schott Lithotec in Meiningen (Germany). These blanks have a TaN-based absorber layer and a SiO 2 buffer layer. During process development the e-beam lithographic behaviour as well as the patterning performance of the material were studied and tuned to meet first EUV mask specifications. For production of the ASML set-up mask the new process was applied to a high performance EUV blank from Schott Lithotec. This blank has absorber and buffer layers identical to the dummy blanks but a multilayer is embedded which is deposited on an LTEM substrate. The actinic behaviour of the multilayer and the flatness of the substrate were tuned to match the required mask specifications. In this article we report on the development of the mask manufacturing process and show performance data of produced EUV full field scanner masks. Thereby, special attention is given to the ASML set-up mask.