Fig. 1. Scanning electron micrographs of Rh sample exposed to Sn thermal vapor at room temperature^[10]. (a) Exposure dose of 2.5×10¹⁵ cm^-2; (b) exposure dose of 3.5×10¹⁶ cm^-2

Fig. 2. Abundance of ion kinetic energy^[11]

Fig. 3. Temporal and spatial characteristics of LPP light source^[18]. (a) Temporal view of laser pulses used to produce EUV; (b) spatial view of target formation and EUV generation process

Fig. 4. Concept of magnetic debris mitigation scheme^[25]

Fig. 5. Photograph of the inner side of an experimental chamber in which a low pressure (argon) gas is irradiated with a pulsed beam of EUV photons^[34](blueish glow at the position where the EUV beam travels indicates the interaction between the EUV photons and the gas)

Fig. 6. Circuit diagram of the plasma source setup^[38]

Fig. 7. Change in tin cleaning rate along the radius of discharge electrode^[44]

Fig. 8. Illustration of temperature-dependent allotropic transformation between α-phase gray tin and β-phase white tin^[48]

Fig. 9. Adsorption, diffusion, and dissociation of large hydrocarbons into a graphitic-like, but partially hydrogenated, layer by EUV radiation or secondary electrons^[64]

Fig. 10. Ternary phase diagram of bonding in amorphous carbon-hydrogen alloys^[65]

Fig. 11. Process of chemical reaction mechanism^[73]

Fig. 12. Atomic hydrogen annealing apparatus^[80]. (a) Principle diagram; (b) internal photograph

Fig. 13. Model of degradation of the Mo/Si multilayer under EUV radiation^[88]

Fig. 14. Relationship between reflectivity and thickness of capping layer^[96]

Fig. 15. Experimental and simulated X-ray reflectivity (XRR) data^[101]. (a) As-deposited sample; (b) sample annealed at 400 ℃ for 20 min (inset: layered model used in simulation)

Fig. 16. Schematic of degradation process in protective TiO₂ film^[106]. (a) Annealing test process of the thin film samples; (b) EUV irradiation process during LPP light source operation

Fig. 17. Low energy ion scattering spectra of ZrO₂ layers grown on a Si (100) substrate with 5 nm amorphous silicon as the bottom layer^[115]. (a) High-O ZrO₂ layers (0.3‒3.4 nm); (b) low-O ZrO₂ layers (0.3‒1.7 nm) (insets: magnified view of the Si peak and layered model of deposition structure)

Fig. 18. Production of void-free, self-limiting carbon layer from ethanol adsorption on a hydroxylated silicon surface of the Mo/Si multilayer^[117]