Measuring the EUV-induced contamination rates of TiO2-capped multilayer optics by anticipated production-environment hydrocarbons

摘要: The primary, publicly reported cause of optic degradation in pre-production extreme-ultraviolet (EUV) lithography systems is carbon deposition. This results when volatile organics adsorb onto surfaces and then are cracked by EUV-induced reactions. Hence the deposition rate depends on adsorption-desorption kinetics molecule-surface system as well basic photon-stimulated reaction rates, both which may vary significantly for different organic species. goal our ongoing optics-contamination program to estimate contamination species expected tool environment exposing samples in-band 13.5 nm light from synchrotron presence fixed partial pressures admitted gases. Here we report preliminary rates TiO 2 -capped observed resist-outgassing measurements (benzene, isobutene, toluene tert-butylbenzene) pressure range (10 -6 10 -4 ) Pa all display an unexpected logarithmic dependence pressure. scaling agreement with previous EUV exposures other at NIST independent coverage performed Rutgers University. These consistent a molecular desorption energy that decreases due interactions (Temkin model). Use proper law critical estimating lifetimes extrapolating over 3-to-6 orders magnitude between accelerated-testing tool-environment pressures.