Ordered nanoporous alumina has recently been considered as a template for pattern transfer by MeV ion irradiation. Porous alumina of thickness 500 nm has already been used as a mask for low energy heavy ion implantation. However, in order to apply this material as a template for production of structures with higher aspect ratios, lighter ions with MeV energies and larger penetration depth should be used. The aim of this contribution is to examine the transmission of such ions through alumina templates with sufficient thickness to mask ions that are not passing the pores. A careful orientation of the pores in the direction of the incident beam is therefore needed since the acceptance angle for ions passing through the pores decreases with increasing thickness.

Typical size of pores in the investigated alumina foils was 70 nm with a repetition frequency of 100 nm. Transmission through the foil and the energy of transmitted MeV ions were measured for aligned alumina foils by standard backscattering technique. It was shown that the sample transmission is a characteristic of each sample, but for some investigated samples the proportion of transmitted ions was the same as the relative area covered by pores. The energy spectra of transmitted ions were used to further evaluate the quality of foil templates for pattern transfer. It was shown that 2 μm thick alumina films can mask 3 MeV O+ ions, which can be used for ion lithography in polymer materials.