Controlled degradation and ablation of polymer surfaces by ultraviolet laser radiation

Abstract

When pulsed ultraviolet laser radiation falls on the surface of an organic polymer the material at the surface is spontaneously etched away to a depth of 0·1 to several microns. The process is characterized by the control which can be exercised over the depth of etching by controlling the temporal width of the laser pulse and its fluence (energy per unit surface area of the polymer) and by the lack of detectable thermal damage to the substrate. The material that is removed by etching consists of products ranging from atoms to small fragments of the polymer. They are ejected at supersonic velocities. This photoetching technique is useful in patterning polymer films since it requires no special sensitization of the polymer, no wet development step, and is potentially capable of as high a resolution as any wet patterning method. © 1987.