The effect of local fluence on the micropatterning of poly(ethylene terephthalate) foils through proton beam writing

In this work, we investigate the influence of ion fluence on the development of microstructures produced by 2.2 MeV H + impinging on 12-μm-thick poly(ethylene terephthalate) (PET, Mylar ® ) foils. Several lines of 1 × 100 pixels corresponding to approximately 2.5 × 101.5 µm 2 were patterned on PET foils using different ion fluences (from 10 12 to 10 17 H + /cm 2 ) and etching times (from 1 to 60 min). We observe the presence of three different behaviors according to the ion fluence. Long etching times are necessary to open the structure in the low fluence regime, while moderate fluences require shorter etching times. In the high fluence regime, a more complex scenario emerges where short etching times lead to structures either fully or partially developed.