Ultra-thin, ultra-low density films for EUV lithography

1. A nanostructure film comprising:

a plurality of carbon nanofibers that are intersected randomly to form an interconnected network structure in a planar orientation, the interconnected network structure having a thickness ranging from a lower limit of 3 nm to an upper limit of 100 nm, and a minimum EUV transmission rate of 92%,

wherein the plurality of carbon nanofibers includes at least 50% of double-walled carbon nanofibers.

2. The nanostructure film according to claim 1 , wherein the thickness ranges from the lower limit of 3 nm to an upper limit of 40 nm.

3. The nanostructure film according to claim 1 , wherein the thickness ranges from the lower limit of 3 nm to an upper limit of 20 nm.

4. The nanostructure film according to claim 1 , wherein an average thickness of the interconnected network structure is 11 nm.

5. The nanostructure film according to claim 1 , wherein an EUV transmission rate rises to above 95%.

6. The nanostructure film according to claim 1 , wherein an EUV transmission rate rises to above 98%.

7. The nanostructure film according to claim 1 ,

wherein the plurality of carbon nanofibers further includes single-walled carbon nanotubes and multi-walled carbon nanotubes, and

wherein a number of walls of single-walled carbon nanotubes is one, a number of walls of the double-walled carbon nanotubes is two, and a number of walls of the multi-walled carbon nanotubes is three or more.

8. The nanostructure film according to claim 7 , wherein the single-walled carbon nanotubes account for a percentage between 20-40% of all carbon nanotubes, double-walled carbon nanotubes account for a percentage 50% or higher of all carbon nanotubes, the remaining carbon nanotubes are multi-walled carbon nanotubes.

9. The nanostructure film according to claim 7 , wherein the single-walled carbon nanotubes account for more than 20% of all carbon nanotubes, double-walled carbon nanotubes account for more than 75% of all carbon nanotubes, the remaining carbon nanotubes are multi-walled carbon nanotubes that account for a remaining percentage of all carbon nanotubes.

10. The nanostructure film according to claim 8 , wherein the difference of any two EUV transmission measurements from the same nanostructure film at any focused area is less than 5%.

11. The nanostructure film according to claim 10 , wherein the difference of any two EUV transmission measurements from the same nanostructure film at any focused area is less than 2%.

12. The nanostructure film according to claim 11 , wherein the difference of any two EUV transmission measurements from the same nanostructure film at any focused area is less than 0.4%.

13. The nanostructured film according to claim 1 , wherein the interconnected network structure has a deflection of less than 3.5 mm under a flow rate of 10 sccm.

14. The nanostructured film according to claim 13 , wherein the deflection is less than 0.6 mm under a flow rate of 10 sccm.

15. The nanostructured film according to claim 1 , wherein the interconnected network structure has a deflection of less than 0.1 mm under a flow rate of 3.5 mbar/second.

16. The nanostructured film according to claim 1 , wherein the interconnected network structure produces a scattering of less than 0.3% under EUV irradiation.

17. The nanostructured film according to claim 1 , wherein the nanoparticles are conformally coated with a metal, metal oxide or nitrides, the metal being selected from boron, ruthenium, zirconium, niobium, molybdenum, rubidium, yttrium, strontium, or rhodium.

18. The nanostructured film according to claim 5 , wherein the nanostructured film has an areal density of about 0.2 μg/cm 2 to about 6.0 μg/cm 2 .

19. The nanostructured film according to claim 1 , wherein the interconnected network structure with a size of 140 mm×110 nm has a deflection of less than 2.5 mm under a flow rate of 3.5 mbar/second.

20. The nanostructure film according to claim 19 , wherein the deflection is less than 0.5 mm.

21. The nanostructure film according to claim 1 , wherein an EUV transmission rate is in a range between the minimum transmission rate of 92% and a maximum transmission rate of 99%.

22. A pellicle, comprising:

a pellicle border defining an aperture, and

at least one nanostructured film mounted to the pellicle border and covering the aperture,

wherein the at least one nanostructured film includes:

a plurality of carbon nanofibers that are intersected randomly to form an interconnected network structure in a planar orientation, the interconnected network structure having a thickness ranging from a lower limit of 3 nm to an upper limit of 100 nm, and a minimum EUV transmission rate of 92%,

wherein the plurality of carbon nanofibers includes at least 50% of double-walled carbon nanofibers.

23. The pellicle of claim 22 , wherein the aperture of the pellicle border is 140 mm×110 mm and the at least one nanostructured film has a deflection less than 2.5 mm under a flow rate of 3.5 mbar/second.

24. The pellicle of claim 23 , wherein the deflection is less than 0.5 mm.

25. A method of performing EUV lithography, comprising transmitting EUV radiation through a pellicle,

the pellicle including:

a pellicle border defining an aperture, and

at least one nanostructured film mounted to the pellicle border and covering the aperture,

wherein the at least one nanostructured film includes:

a plurality of carbon nanofibers that are intersected randomly to form an interconnected network structure in a planar orientation, the interconnected network structure having a thickness ranging from a lower limit of 3 nm to an upper limit of 100 nm, and a minimum EUV transmission rate of 92%,

wherein the plurality of carbon nanofibers includes at least 50% of double-walled carbon nanofibers.