Rapid deep micromachining of polytetrafluoroethylene by MeV ion bombardment in oxygen-rich atmospheres

Polytetrafluoroethylene (PTFE) displays an unusual behaviour when exposed to energetic light ions. Whereas other polymers tend to go black and degrade when exposed to MeV proton beams in air, rapid ablation of PTFE is observed. This rapid direct etching of PTFE with protons was investigated in a series of experiments and it was found that the presence of oxygen was required to obtain the high etch rates observed. The phenomenon described here offers a mechanism for fabricating high aspect ratio PTFE microstructures.