Proc. SPIE. 11323, Extreme Ultraviolet (EUV) Lithography XI
KEYWORDS: Metals, Manufacturing, Scanning electron microscopy, Photoresist materials, Extreme ultraviolet, Line width roughness, Extreme ultraviolet lithography, Photoresist processing, Semiconducting wafers, System on a chip
For generations lithographers have worked to overcome the difficulties associated with defect mitigation, and since EUV lithography has become mature enough for HVM this concern is warranting ever increasing attention to make such processes profitable. Even though much of the EUV defect effort is focused on stochastic defects, in this work we attempt to assess and understand process defects associated with the interaction between different films in an EUV stack. By understanding the behavior of specific underlayer materials and their chemistry within a given environment we have attempted to tune the surface energies to match the photoresist in the stack. With the correct process changes being applied, we have then worked to correlate the proper matching of surface energies with process defects. The current focus of our work is specifically line collapse, and we believe that developing a fuller understanding of the film interactions will ultimately lead to a more robust EUV process for HVM. We hereby present our work utilizing the SCREEN DUO coat develop track system with an ASML NXE:3300 in the imec Leuven cleanroom facility.
Photo-thermo-refractive glass is a promising material because it combines the properties of several monofunctional materials in it. These glasses can be doped with rare earth ions and can then be used for many practical applications. But the major problem is the low absorption coefficient. So, a lot of research has been done to grow silver nanoclusters and nanoparticles for improving the spectroscopic properties of rare-earth ions. In this study we present a way to transfer energy from silver clusters to Eu3+ ions in the PTR glass. These results can be used for developing warm white LEDs and down converters for solar cells.
Optical fiber resonator (OFR) sensor is presented for bulk liquid refractive index (RI) sensing. The sensing mechanism relies on the spectral shifts of whispering gallery modes (WGMs) of OFRs which are excited using a tapered fiber. OFR liquid RI sensor is fully characterized using water solutions of ethanol and ethylene glycol (EG). A good agreement is achieved between the analytical calculations and experimental results for both TE and TM polarizations. The detection limit for bulk RI is calculated to be between 2.7 – 4.7 × 10−5 refractive index unit (RIU). The OFR sensor provides a robust, easy-to-fabricate and sensitive liquid refractive index sensor which can be employed in lab-on-a-chip applications.