Direct-etching studies of polymer films using a 157-nm F_2 laser

The ablation of polyimide, polyethylene terephthalate, and polyethylene films at 157 nm has been studied using an F2 laser working in an He atmosphere, which considerably simplifies the experimental procedure. Ablation thresholds have been estimated from thermal-coupling measurements on the films. Contact-printing results indicate that polyimide should be a useful medium for recording submicrometer patterns.