EUV spectrum of high power LPP source

EUV scanners have been adopted worldwide for High-Volume Manufacturing (HVM) of sub-10 nm lithography, utilizing Laser-Produced Plasma (LPP) Sources to generate EUV photons. The output spectrum of the LPP Source is relevant for several aspects of the scanner, such as optimizing reticle stacks and pellicles and for optimizing resist for maximum sensitivity and imaging contrast. Also, the ion fluxes and energies of the scanner plasma will depend on the details of the full UV spectrum. This paper will describe full-UV spectrum measurements from 5 to 400 nm, measured at the output point of an LPP Source, using a proprietary transmission grating spectrometer. Impact of the different spectral regions will be discussed for reticles, pellicles, resist, and scanner plasma. Finally, some options will be described to reduce or filter out unwanted spectral components if desired.