2. Status of World Research in EUV Lithography
The EUV lithography for projecting circuit patterns that uses the 13.5-nm extreme ultraviolet light and reflection-type optics was proposed and first studied by Kinoshita (currently with University of Hyogo) and others from NTT in Japan.1) Almost simultaneously, in the US EUV lithography was beginning to be studied at the Bell Laboratories and continued to be researched at the National Institute in the ’90s.
In 1997, the EUV Limited Liability Company (EUVLLC) was established to start extensive research on the EUV lithography.2) Inspired by the establishment of the EUVLLC, the Extreme UV Concept Lithography Development System (EUCLIDES) and the ASET EUV Laboratory were started in Europe and Japan, respectively. As the result, extensive research was started in the US, Europe and Japan. 3), 4)
Later on, SEMATECH took over the research and has conducted intensive research activities at Albany Nanotech Institute and Lawrence Berkeley National Laboratory (LBNL).5) In Europe, research programs including MEDEA+ and More Moore had aggressively worked on EUV lithography research, and the EUV Entry Point Technology (ECEPT) project has currently taken over the leadership in this research.
Carl Zeiss and ASML have been leading and aggressively working on development of EUV lithography tools. For research and development, they installed experimental EUV lithography tools at IMEC to proceed with development of EUV application technologies. In Japan, followed by the ASET EUV Laboratory, EUV lithography has been extensively studied at Semiconductor Leading-Edge Technologies, Inc. (Selete). At Selete, Nikon and Canon developed lithography tools EUV-1 and SFET, respectively. Mask and photoresist technologies also were developed and evaluated there.6)
But, ASET and Selete concentrated on development of the mask and resist technologies. For this reason, the Extreme Ultraviolet Lithography System Development Association (EUVA) was established in 2001 to start extensive research on the EUV light source and lithography tools. At the EUVA, five equipment companies (Ushio, Canon, Nikon, Komatsu, and Gigaphoton) and 4 semiconductor device manufacturers (Toshiba, NEC, Fujitsu, and Renesas Technology) participated in this project as members.
In addition, a project led by Osaka University and sponsored by the Japan Ministry of Education, Culture, Sports, Science and Technology (MEXT) was started in 2011 to conduct theoretical and fundamental research on the EUV light source plasma, in conjunction with the EUVA. The research activities at the EUVA were completed in March 2011. However, the EUV mask and photoresist technologies have continued to be studied at the EUVL Infrastructure Development Center (EIDEC) from May 2011.