**7. Conclusion**

392 Recent Advances in Nanofabrication Techniques and Applications

Sample Rh 318 Rh 319 Rh 320 Area Ra (nm) 18.5 14.8 2.00 Area RMS (nm) 22.4 19.4 3.20 Average height (nm) 60.9 16.7 1.78 Max. height (nm) 137 100 26.4

Table 1. Two-dimensional (10x10 μm) atomic force microscope (AFM) images and

roughness values calculated with the AFM computer analysis program.

Sample Rh 321 Rh 323 Area RMS (nm) 14.12 0.11 Max. height (nm) 89.00 2.05 Feature Area (um2) 22.98 n/a Feature Coverage (%) 91.9% n/a

and energetic Sn only (right) samples.

morphology of the samples and the fluence of Xe+.

Table 2. Two-dimensional (5x5 μm) atomic force microscope (AFM) images and roughness values calculated with the AFM computer analysis program for Rh thermal Sn only (left)

The AFM investigated the morphology of the samples. Table 1 and 2 illustrate the results. As the fluence of the samples is increased, it is found that the height, the roughness and the general size of the features decrease significantly. This is likely due to the increase in sputtering of Sn caused by the higher Xe+ fluence. Rh 318 has the largest roughness and height values, at 22.4 nm and 137 nm respectively, but has the lowest fluence of the sample set. Rh 320 on the other hand has the smallest values for roughness and height, 3.20 nm and 26.4 nm, but the largest fluence of the set. This shows a direct correlation between the

10x10 μm 10x10 μm 10x10 μm

5x5 μm 5x5 μm

In conclusion, the success of EUV lithography as a high-volume manufacturing patterning tool remains elusive although great progress has been made in the past half decade. One main challenge is the plasma-facing components (e.g. electrodes, collector mirrors and debris mitigation shields) lifetime that ultimately impact the EUV power available for exposure.
