Effect of chemical etching on poly(methyl methacrylate) irradiated with slow highly charged ions

We have recently demonstrated that individual slow highly charged ions are able to produce nano-sized pits on poly(methyl methacrylate) surfaces as a result of direct ablation due to the deposition of their high potential energy, if this energy exceeds a critical minimum value. By exposing irradiated samples to a suitable etchant, such pits can be revealed even below this potential energy threshold as latent damage zones are removed. Existing pits grow both in diameter and in depth after contact with the etchant with different etching dynamics for both dimensions. Systematic studies on the response of irradiated samples to a chemical developer are presented. (paper)