X-RAY PHOTOEMISSION-STUDY OF VARIOUS POLYIMIDE CLEANING PROCESSES BEFORE METAL-DEPOSITION

In order to determine the best chemical surface state of a polyimide ( PI) sample to obtain good metal polymer adhesion, the chemical changes occurring on the PI surface following different treatments were studi ed by X-ray photoelectron spectroscopy. The effect of alcohol ultrason ic cleaning, optionally followed by PI heating, as well as the effects of exposure to an Ar and to an 0 plasma were therefore analyzed. It w as concluded that an efficient way to treat the PI sample prior to non -reactive metal deposition is simply to clean it in an alcohol ultraso nic bath, then to heat it to approximately 150-degrees-C. Its surface composition becomes very similar to its bulk composition. The adsorbed nitrogen which prevents nucleation of metallic atoms on and below the PI sample is thereby totally desorbed.