Radiation Effects Of Various Ion Beams On Resists Studied By Product Analysis And New Nanosecond Ion Beam Pulse Radiolysis

The ion beam interaction with very thin films (0.5 μm thickness) of a fundamental polymer, polystyrene, was investigated by means of radiation chemistry. Radiation effects on solubility of spin-coated polystyrene films were measured for hydrogen, helium and nitrogen ion beams (0.4 - 3.3 MeV). Measurements were also carried out for 20 keV electrons. By using ion beam pulse radiolysis system, the transient phenomena excited by energetic ion beams were investigated. The time profiles of the excimer fluorescence from ion irradiated polystyrene thin film were measured for hydrogen, helium and nitrogen ions (0.6 - 2.8 MeV). The results for energetic ions were compared with those for low LET radiation, such as fast electron or gamma-ray. Very large differences in radiation effects on solubility and some differences in transient phenomena were found and discussed from the view point of high density electronic excitation.