Spectroscopic investigations of plasma damage of kapton

Kapton (polyimide) has been considered a potential candidate for particle r eduction in plasma etching chambers. However, it is found that the lifetime of kapton's ability to trap particles is limited. Beyond this limit, parti cle contamination becomes serious. In this study, two plasma etching recipe s were used to test the particle/polymer trapping efficiency of kapton. Fou rier transform infrared (FTIR) and ultraviolet (UV)-visible emission spectr oscopies were used to study plasmakapton interactions. It is found that the functional groups change on the kapton surface as observed by IR has a str ong link to the change of features in plasma emission spectra. The increase of IR absorption of CFx (x = 2 and 3) indicates the growth of fluorocarbon polymer on the kapton surface. The kapton surface was damaged, as is indic ated by the change of C=O, -NH2, and C-H IR intensities and the variation o f CN and SiF peaks in UV-visible emission spectra. Spectroscopic data show that kapton has a very good particle/polymer reduction efficiency when usin g a high-polymer recipe but it is not very efficient with an oxygen-rich re cipe. Both IR absorption and UV-visible emission data are correlated to int erpret the mechanisms of plasma damage of kapton. (C) 2000 American Vacuum Society. [S0734-211X(00)05602-X].