COMPARATIVE-ANALYSIS OF ETCHING OF POLYIMIDE FILMS IN PLASMAS IN O2 AND O2-CF4 MIXTURES

The etching of Kapton polyimide films in the positive column of discha rges in O2 and O2-CF4 mixtures has been studied. The rate of mass loss , the rate of release of gaseous products, and the rate of consumption of O2 and CF4 are measured under comparable conditions. A comparison of the particle and mass balances shows that the main etching agent is oxygen, both in O2 plasma and in O2-CF4 mixtures. It is proposed that fluorine atoms initiate etching but through other channels than in an O2 plasma.