Ultraviolet Laser Ablation of Organic Polymer Films

When a pulse (~ 14 nsec half-width) of laser radiation of 193 nm wavelength with a fluence above a threshold value falls on a polymer film, the material at the irradiation site is spontaneously etched away to a depth of 1000 A or more.[1,2] This process has been called Ablative Photo Decomposition’ [3]. The excimer laser which is the source of the 193 nm radiation is capable of providing radiation at other wavelengths such as 249 nm, 308 nm, and 351 nm. Spontaneous etching of the polymer films by the laser beam has been observed at all of these wavelengths [4–7].But there are quantitative differences in the etching process at different wavelengths and with different polymers.