We describe essentially the lithography performed on a new photoresist, called DiaPlate 133. This negative resin has been structured by an x-ray beam produced by a new high brightness synchrotron light source, the Swiss Light Source (SLS) located at Villigen, near Zurich, during a 8 h-run and compared with another well-known resin, SU-8. Then the resins have been structured with ions at CAFI and both techniques are compared. Results and comments are presented underneath. It can be noted that the x-ray and ion beam lithography tests we performed with DiaPlate 133 were the first ones ever realized.

Ion beam lithography is a very powerful technique for 3D direct and maskless writing of resist materials. Light high-energy ions, like protons, can be used to structure these materials. For positive photoresist, like PMMA, this is possible because the protons cause chain scissions in the molecules. Afterwards the irradiated area can be developed in a chemical bath. In this paper, we show the realization of sub-surface channels, or microtunnels, which have been fabricated in only one exposure and without cutting or resurfacing the material. Using our Van-de-Graaff accelerator, the resist (PMMA) has been exposed with high-energy protons (2.7MeV). The range of charged particles in matter is well-defined and depends on the energy. In addition the linear energy transfer is highest at the end of the ion path. Therefore, it is possible to obtain a dose which is sufficient to develop the bottom part of the ion paths but not the top part. Thus, by selecting the energy and the exposure time, a big variety of microtunnels can be realized.