Auger electron spectroscopy (AES) and x-ray photoelectron spectroscopy (XPS) were used to study a problem of poor adhesion of plated Ni/Au contact layers in ceramic electronic packages. XPS surveys showed that the Ni/Au films failed at the Mo contact pad/Ni interface. When the films were stripped, in situ, AES revealed a contamination layer of carbonaceous material on both the contact pad and mating surface of the stripped film. The XPS C Is peak obtained from the approximate to 20-nm-thick carbonaceous contamination layer on a freshly exposed pad surface matched that for the same peak taken from a special mounting wax used in a process step prior to plating. The surfaces of both the contamination and the wax exhibited a characteristic disappearance of the C=O band after approximate to 1 min of Ar-ion sputtering. Plating adhesion was restored after the cleaning solutions used prior to plating were changed more frequently to prevent wax buildup.