NSLS-II Seminar

The unrelenting demand for computer processors and memory with higher speed and capacity is directly connected to higher integration densities and, consequently, the printing of smaller feature sizes. Optical lithography at 193 nm is the current state of the art for manufacturing semiconductor structures. One key to enhance the resolution is to decrease the lithography wavelength. Extreme ultraviolet (EUV) lithography at 13.5 nm is expected to be the next generation lithography. The great leap to the Soft-X-ray spectral range, however, leads to tremendous requirements on the surface roughness of optical components.

Roughness-induced light scattering may drastically reduce the throughput, the resolution, and the contrast in lithographic systems. The measurement and modeling of EUV light scattering are essential for improving the performance of EUV optical components. Furthermore, characterizing the relevant roughness properties even at very early stages in the manufacturing chain of optical components ensures that the desired performance can in fact be achieved.

The talk first provides a brief overview of the EUV/Soft-X-ray related activities at IOF in general including multilayer coatings and diffraction gratings. Special emphasis will be placed on the modeling and measurement of roughness-induced light scattering. An instrument for EUV light scattering measurements at 13.5 nm developed at IOF will be presented. Results of angle resolved scattering measurements of Mo/Si multilayer mirrors for 13.5 nm will be analyzed using simple roughness and light scattering models. Furthermore, a laser light scattering method will be presented that enables the roughness of large collector mirrors for laser-produced plasma EUV sources to be characterized and the performance to be predicted before coating.

If you would like to meet with this speaker please contact the host (midir@bnl.gov) or Peter Takacs (takacs@bnl.gov) to cordinate a time.