Update on the EUVL mask blank activity at Schott Lithotec

Schott Lithotec has introduced all relevant technology steps to manufacture EUV mask blanks in its advanced quality mask blank manufacturing line -- ranging from Low Thermal Expansion Material (LTEM) high quality substrate polishing to low defect blank manufacturing. New polishing and cleaning technologies, improved sputter technology and updated metrology enable us to produce EUVL mask blanks meeting already some of the roadmap requirements. Further R&D is ongoing to path the way to the pilot production of EUV blanks which meet the beta-specifications end of 2005. We present the status of our EUVL substrate program and report on the recent results of our activities for low defect multilayer, buffer and absorber coating including new absorber materials. Recent results from the production of full LTEM EUV blanks with multilayer, buffer and absorber coatings will be presented. Process steps in the EUVL mask blank fabrication in a production environment were characterized in terms of defects; the process improvement potential is discussed. We will also throw a light on the aspects of changed layer properties after a longer period of storage. In addition, special metrology methods for EUVL components are currently being developed within the program. The status of the high throughput EUV-Reflectometer for mask blanks will be presented. We developed new processes to achieve EUVL requirements.