One of the obstacles in the development of EUV lithography in high volume manufacturing is mask contamination 3. We identified the potential of CNTs to contribute to high yield extreme ultraviolet (EUV) lithography, enabling advanced chip manufacturing 1, 2. A solution is needed to extend the CNT pellicle lifetime and coating is discussed as a potential approach to protect the CNT material from hydrogen plasma damage.ĭue to its remarkable thermal, electronic and mechanical properties, carbon nanotube (CNT) material offers a wide range of unique application opportunities.
Transmission, spectroscopic and chemical composition mapping of the exposed free-standing CNT films are used to study the material changes that occur in the scanner-like environment. Optical properties of different pellicles and their ability to withstand high EUV powers in the hydrogen-based environment were tested. single-, double-, multi-walled CNTs and their combinations, are explored as building blocks of an optimized pellicle membrane. It is critical for the pellicle to be stable in the EUV lithography scanner environment which includes hydrogen plasma and heat loads associated with high powers beyond 250 W. Depending on the density and morphology of the CNTs within the film and individual CNT parameters, like number of walls, bundle size, metal catalyst content, purity etc., the optical and thermal properties of the CNT pellicle can be tuned.
Balancing the CNT material properties for the optimal pellicle performance in EUV scanners remains the ongoing research focus. Today the advancement of the CNT material synthesis together with matured methods to fabricate thin CNT membranes make free-standing CNT films a very promising EUV pellicle candidate for high volume EUV lithography. Research on carbon nanotube (CNT) films for the EUV pellicle application was initiated at imec in 2015 triggered by the remarkable optical, mechanical, and thermal properties of the CNT material.
0 kommentar(er)
