Fig. 1. Schematic of the LPP-EUVL source system. Reprinted from Ref. [7].

Fig. 2. Role of the collector in the light source system: the collector collects radiations and reflects them to the IF for subsequent optical path propagation. Reprinted from Ref. [13].

Fig. 3. Calculated reflectance of the 50-bilayer Mo/Si multilayer coating of 6.9 nm periodicity. Reprinted from Ref. [15].

Fig. 4. The black border’s influence on CD errors of the corners and edges of the adjacent field. Reprinted from Ref. [25].

Fig. 5. EUVL system with possible locations for the transmissive SPF.

Fig. 6. Grid transmissive SPF of IR suppression: (a) scanning electron microscopy image of the grid after etching, (b) grid SPF after backside wet etching, (c) grid SPF with a diameter of 90 mm installed for measurement and (d) grid SPF installed in the LPP source system. Adapted from Ref. [19].

Fig. 7. DGL's location and its influence on outgassing suppression. Reprinted from Ref. [31].

Fig. 8. OoB suppression performance with DGLm: (a) complete suppression of DUV radiation (<0.1% transmitted) as measured by PTB; (b) 78% IR suppression as measured off-line by Fourier transform infrared spectroscopy. Adapted from Ref. [31].

Fig. 9. Collector with a grating structure from Gigaphoton, Inc. Reprinted from Ref. [15].

Fig. 10. Schematic of the IR suppression design with the collector integrated with the rectangular substrate grating. Adapted from Ref. [47].

Fig. 11. Schematic of the rectangular multilayer grating.

Fig. 12. Schematic of the blazed multilayer grating.

Fig. 13. 2D pyramid multilayer grating on the collector: (a) design of the multilayer pyramids; (b) UV-suppression performance of Si pyramids and the Mo/Si multilayer mirror in (a); (c) EUV performance comparison of Si pyramids and the Mo/Si multilayer mirror in (a). Adapted from Refs. [53,60].

Fig. 14. Design of the rectangular substrate grating: (a) schematic of 1D rectangular substrate grating; (b) schematic of 2D rectangular substrate grating by IOF. Adapted from Refs. [53,62].

Fig. 15. (a) AFM image of diamond-turned patterns and (b) the mechanical polished surface of (a). Reprinted from Ref. [49].

Fig. 16. HSFR results (AFM) of adding a smoothing layer by Rigaku: (a) diamond-turned surface sample; (b) smoothed diamond-turned surface sample; (c) 0.14–0.29 nm rms over 2.2 μm scans; (d) 0.29–0.39 nm rms over 8.7 μm scans of the grating surface. Adapted from Refs. [8,15].

Fig. 17. Different measurements for roughness at different spatial frequencies. Adapted from Ref. [70].

Fig. 18. WLI analysis of a dual-layer rectangular substrate grating structure by the IOF. Reprinted from Ref. [62].

Fig. 19. ARS instrument ALBATROSS for scattering measurements in the UV-VIS-IR range. Components include laser sources (1), mechanical chopper for lock-in amplification (2), attenuation filters (3), beam preparation optics (4), polarizer (5), sample (6) and detector (7). Adapted from Ref. [62].

Fig. 20. EUV-ARS for the characterization of nanometre structures exposed by PTB. Reprinted from Ref. [87].

Fig. 21. Mechanics of the EUV reflectometer by PTB. Reprinted from Ref. [89].

Fig. 22. Schematic of the IR suppression test stand. Reprinted from Ref. [8].

Fig. 23. (a) Schematic of the collector integrated with the blazed substrate grating and (b) schematic of the collector with power recycling mirrors. Reprinted from Refs. [96,97].