Etching techniques using a collimated ion beam for the realization of waveguides

The elaboration of polymer guiding structures in passive and active optoelectronic components needs an etching stage. As high anisotropy is required for the etching process, the use of a low energy ion beam proves to be better than etching techniques by wet process. Thus, we developed two etching techniques called reactive ion beam etching (RIBE) and ion beam assisted etching (IBAE) which use, in the first case, a reactive ion beam, and in the second one, argon or oxygen ions with a reactive flux (O2) towards the target. The comparative study between RIBE and IBAE etching enables us to get identical optimal etching rates but with different ion energies (for RIBE the optimal energy is 2.5 keV and for IBAE it is 6 keV). In the last case, for which there is ion collision with the oxygen flux, we can notice we must provide enough energy to the ions for them to reach the target and to transfer some of the energy to O2 molecules. We showed, for identical etching rates the IBAE technique can present the advantage of having a higher anisotropic etching ratio than the RIBE technique.