The influence of 10 nm Si intermediate layers and84Kr+implantation on the adhesion of 30 nm Ni films on poly [N,N‐(p,p’‐oxydiphenylene) pyromellitimide] (PI) substrates was examined. The Ni/Si/PI specimens were implanted with either 5×1015, 1×1016, or 5×1016Kr/cm2at a specimen temperature of less than 100 °C. Surface topography remained smooth after the 5×1015and 1×1016Kr/cm2implants. In contrast, the 5×1016Kr/cm2implant resulted in extensive island formation, which destroyed the integrity of the Ni films. Auger electron spectroscopy (AES) depth profiles of the as‐deposited films showed graded Ni distributions throughout the Si intermediate layers, which form abrupt interfaces with the PI substrates. After implantation with 5×1015or 1×1016Kr/cm2implants, the Si intermediate layers become highly oxidized. Significant quantities (15 to 20 at. % in the Ni film) of carbon were transferred into the Ni films from the PI substrates, but the interface to the PI substrates remained sharp. The Ni that was present in the as‐deposited Si layers appears to segregate out of these layers after the ion‐induced oxidation. X‐ray photoelectron spectroscopy (XPS) analysis showed that the chemistry of the Si interfacial layers changed from a mixture of SiO and Ni2Si in the as‐deposited specimens to almost entirely SiO2in the implanted specimens. The adhesion of the Ni films was examined using a scratch test. The as‐deposited Ni films were removed at a force of 4 N with failure at the Si/PI interface. After ion implantation, the films were removed at a force of only 2 N, and the failure occurred at the Ni/SiO2interface. This reduction in adhesion, which was in startling contrast to the adhesion enhancement obtained by implanting Ni/PI specimens with28Si+, was attributed to the preferential formation of SiO2during the84Kr+ion bombardment. It was concluded that the Si must be implanted into both the Ni films and the PI (or other oxygenated polymers) in order to maximize the adhesion enhancement of Ni films.