Changes in refractive index and in chemical state of synchrotron radiation irradiated fluorinated polyimide films

Changes in refractive index and in film thickness caused by synchrotron radiation are studied in a fluorinated polyimide (6FDA/TFDB). The index at 589.6 nm increased by 1.3% and the thickness decreased by 0.69% for 8‐μm‐thick film after 30 min irradiation. X‐ray photoelectron spectroscopy analysis was performed on the modified surfaces after synchrotron radiation exposure. From the present data the synchrotron radiation leads to production of a fluorine‐poor surface.