In this letter, we study Ta/parylene-F (PA–F) buried interfaces using x-ray photoelectron spectroscopy. We found that the Ta–F bond was formed at the Ta/PA–F interface after depositing a layer of thin Ta film(<50 Å).For theAr+orO2plasma pretreated PA–F surface, in addition to the Ta–F bond, a Ta–C bond was observed at the buried interface after Ta metallization. The Ta–C bond may be responsible for the enhancement of Ta/PA–F adhesion. ©1998 American Institute of Physics.