Soft x-ray lithography

1 Aegerter, MA Puetz, J Gasparro, G., and Al-Dahoudi, N. (2004) Versatile wet deposition techniques for functional oxide coatings. Opt. Mater., 26, 155-162. 

4 Bohannan, E.W., Gao, X.R., Gaston, K.R., Doss, C.D., Sotiriou-Leventis, C, and Leventis, N. (2002) Photolithographic patterning and doping of silica xerogel films./. Sol-GelSci. Technol., 23 (3), 235-245. 

(2001) EJV light irradiation of nanocomposite Si02-Ti02 thin films derived by a sol-gel method. J. Inorg. Mater., 16 (6), 1174-1180. 

6 Soppera, A., Feullade, M., Croutx -Barghon, C., and Carrd, C. (2005) Mechanical properties of IW-photopolymerizable hybrid sol-gel films investigated by AFM in pulsed force mode. Prog. Solid State Chem., 33 (2-4), 233-242. 

7 Innocenzi, P. and Brusatin, G. (2004) A comparative FTIR study of thermal and photo-polymerization processes in hybrid sol-gel films. J. Non-Cryst Solids, 333, 137-142. 

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Projection soft x-ray lithography, also called EUV lithography, was invented independently in the 1980s by research teams at NTT in Japan and at Bell Laboratories in the United States,who were inspired by the availability of mirrors of reasonable efficiency at soft x-ray wavelengths (X. 4-40 nm). Summarized... 

R.J. Rosner, R. Feder, A. Ng, F. Adams, P. Celliers, R.J. Speen Nondestructive single-shot soft X-ray lithography and contact microscopy using a laser-produced plasma source. Appl. Spectr. 26, 4313 (1987)... 

Soft X-ray lithography has also been widely used for patterning sol-gel films [16] a possible alternative method is the exposure to hard X-rays that are characterized by a higher energy. 

The e-beam sensitivity is not particularly high being about 300 fiC/crn for an accelerating voltage of 20 to 30 kV which is comparable to PMMA. However, the contrast is extremely high with a 7-value equal to 8 (8). The resist has been reported to be sensitive to ion beams (9) and to soft x-ray irradiation as well. Thus, the inorganic resists are applicable to all non-optical lithographies. 

Spears and H.I. Smith, High resolution pattern replication using soft X rays, Electron Lett. 8, 102 (1972) E. Spears and H.I. Smith, X ray lithography A new high resolution replication process, Solid State Technol. 15(7), 21 (1972). 

Kinoshita, T. Kaneko, H. Takei, N. Takeuchi, and S. Ishihara, Study on x ray reduction projec tion lithography, Proc. of 47th Autumn Meeting of the Japan Soc. ofAppl. P/iyi"., PaperNo. 28 ZE 15 (1986) H. Kinoshita, K. Kurihara, Y. Ishii, and Y. Torii, Soft x ray reduction lithography using mul tilayer mirrors, J. Vac. Sci. Technol. B 7, 1648 (1989) T. Namioka, Current research activities in the field of multilayer for soft x rays in Japan, Revue Phys. Appl. 23, 1711 1726 (1988). 

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