In June 21, 2017, the final acceptance meeting of “the research on the key technologies of extreme ultraviolet(EUV) lithography”, which is one project of the “Manufacturing equipment and complete process of very large scale integrated circuit” project supported by National Science and Technology Major Project of the Ministry of Science and Technology of China, was held in Changchun Institute of Optics, fine Mechanics and Physics, Chinese Academy of Sciences(CIOMP). The office of administration for implementing major project organized the meeting. The panel experts fully recognized the achievements of the project and approved the final acceptance of the project. The successful implementation of the project is an important step forward in the development of Chinese EUV lithography technology.

EUV lithography is a kind of projection lithography using the 13.5nm wavelength light. It is a reasonable extension of traditional lithography towards shorter wavelength. As the next generation of lithography, EUV lithography has been entrusted with the mission to save Moore's law. EUV lithography technology represents the highest level of applied optics. As a prospective research, this project consists of project indicators with highest standards, technical difficulties with tremendous bottlenecks, high innovation, as well as the serious technical blockade from developed countries.

Since 1990s, CIOMP has been focused on the research of EUV/X-ray imaging technology, especially in EUV light source, ultra-smooth surface polishing technology, EUV multilayer and correlation technology. And those aforesaid techniques form the applicative foundation of EUV optics. In 2002, the first EUV lithography prototype in China was developed, which verified the EUV lithography in principle. In 2008, EUV lithography technology was listed as a key research task in "32-22nm equipment technology forward-looking research" by the major project. CIOMP carried out the project of “The research on the key technologies of extreme ultraviolet lithography” as a leading organization, together with partners such as CAS Institute of Optics and Electronics, CAS Shanghai Institute of Optics and Fine Mechanics, CAS Institute Microelectronics, Beijing Institute of Technology, Harbin Institute of Technology, Huazhong University of Science and Technology.

The research team insisted the scientific spirit of perseverance, concentrates on the research, and accumulates propound knowledge. With eight years’ hard work, they have mastered a series of core technologies that limit the development of Chinese EUV lithography, such as ultrahigh accuracy aspheric mirror fabrication and testing, EUV multilayer, projection system integration and test, etc. A two-mirror EUVL objective system with the wave-front aberration better than 0.75 nm RMS was developed successfully, and a EUV lithography exposure apparatus was constructed. Using the apparatus, they achieved the first photoresist exposure pattern with 32 nm linewidth by EUV lithography in China. They established a relatively perfect research and development platform for key technology of exposure optical system, complete successfully the research contents and tasks of national major project, achieve leapfrog development in EUV optical imaging technology, and enhance significantly the core technologies of Chinese EUV lithography. At the same time, the implementation of the project contributed the establishment of a stable research team, and trained talents for our country to achieve sustainable development in the next generation lithography technology.

Group photo taken in the final acceptance meeting scene( Photo by CIOMP)