Excimer lamp-induced decomposition of platinum acetylacetonate films for electroless copper plating

Photo-induced decomposition of platinum acetylacetonate films using an excimer VUV source of 172 nm radiation is reported. VUV irradiation of a substrate coated with platinum acetylacetonate film results in the formation of platinum, which acts as an activator for copper plating by means of a subsequent electroless bath process. Selective copper patterns can thus be formed by employing patterned VUV irradiation through a quartz contact mask to dimensions approaching the submicron level. The platinum films formed and the platinum acetylacetonate layers used were characterised using ultraviolet spectrophotometry (UV) and Fourier transform infrared (FTIR) spectrometry. The photo-decomposition of the platinum compounds was found to be a function of both the UV dose and chamber pressure during irradiation. The morphology of the copper layers was investigated with a scanning electron microscope (SEM). (C) 1999 Elsevier Science Ltd. All rights reserved.