Surface Modification of Polytetrafluoroethylene and the Deposition of Copper Films

Abstract

AbstractEnhancement of the adhesion of thin copper films on polytetrafluoroethylene substrates was found when the substrate surface was irradiated with a pulsed UV excimer laser prior to metal deposition. The interaction between the laser and the polymer was examined by characterizing the neutral and charged species emitted from the surface during irradiation. The nature of the species emitted indicates that significant chemical modification of the polymer surface occurs. In addition to chemical modification, the interaction with the laser also alters the surface morphology of the polymer. Irradiation at fluences of ∼ 0.6 J/cm2 results in an overall planarization of the surface, whilst irradiation at higher fluences results in the formation and enlargement of voids and localized melting.