Change of hydrogen concentration after ion beam irradiation on polyimide films with 100-400 °C annealing

Irradiation damage in the several thickness polyimide films induced by 2.0 MeV He ions has been evaluated by Rutherford backscattering (RBS) and elastic recoil detection (ERDA) methods. For the samples without annealing, gradual decrease of hydrogen content has been observed with the increase of ion dose. After 5 min annealing at 100 °C, a large amount of hydrogen atoms disappeared suddenly. Then small and continuous depletion of hydrogen content was also observed after ion beam irradiation. After 5 min annealing at 300 °C, hydrogen concentration has recovered for the 100 °C annealed film in the case of no ion beam irradiation. Initial depletion rate of hydrogen for annealing and change of hydrogen content for the successive ion beam irradiation was found to be dependent on the film thickness.