Micro-fabrication of biodegradable polymers using focused ion beam

Microfabrication of biodegradable polymers such as poly(butylene succinate-co-adipate) (PBSA) and poly(Ε-caprolactone) (PCL) were demonstrated using focused ion beam (FIB) with maskless direct etching. As the result, the micro structures of PBSA and PCL were obtained. The etching depth of both PBSA and PCL were increased with increasing FIB fluence, and the etching rates were estimated to be about 1.3 x 10^-18 μm/(ions cm^-2) and 1.2 × 10^-18 μm/(ions cm^-2), respectively. Moreover, very thin films of PBSA and PCL were made by spin-coating method. The thicknesses of the spin-coated samples were about 200 nm, and the surface roughness was less than 10 nm (RMS). The fine structures such as micro-gear of PBSA and PCL were obtained without solid debris. The line width of the fabricated structure was about 250 nm.