Influence of the laser-spot diameter on photo-ablation rates

The dependence of the ablation rate of various materials on the laser spot diameter on the sample surface has been investigated. The experiments have been performed with excimer lasers at the wavelengths 193, 248 and 308 nm. Polymers, aluminum oxide ceramics, and glasses have been ablated under vacuum and ambient atmosphere conditions. In general, all materials show a more or less pronounced increase of the ablation rate with decreasing spot diameter in the range of 10–200 μm if pulses with nanosecond pulse durations are applied. For ultrashort pulses (500 fs) at 248 nm this diameter dependence is not observed. The expansion of the ablation plume over areas of different size seems to be the main reason for this effect.

[1]  R. Srinivasan,et al.  Ultraviolet Laser Ablation of Organic Polymer Films , 1989 .

[2]  P. Simon.  Time-resolved ablation-site photography of XeCl-laser irradiated polyimid , 1989 .

[3]  M. Eyett,et al.  Influence of the beam spot size on ablation rates in pulsed‐laser processing , 1987 .

[4]  D. Bäuerle.  Chemical processing with lasers , 1986 .

[5]  R. Srinivasan,et al.  Dynamics of UV laser ablation of organic polymer surfaces , 1986 .

[6]  S. Szatmári,et al.  Novel achromatic distributed feedback dye laser for subpicosecond operation , 1987 .

[7]  R. Srinivasan,et al.  Self-developing photoetching of poly(ethylene terephthalate) films by far-ultraviolet excimer laser radiation , 1982 .

[8]  Rangaswamy Srinivasan,et al.  Nanosecond photoacoustic studies on ultraviolet laser ablation of organic polymers , 1986 .

[9]  Raghavan Srinivasan,et al.  Ultraviolet laser ablation of polyimide films , 1987 .

[10]  Sylvain Lazare,et al.  Ultraviolet Laser Photoablation of Polymers: A Review and Recent Results , 1989 .

[11]  G. Koren.  Temporal measurements of photofragment attenuation at 248 nm in the laser ablation of polyimide in air , 1987 .

[12]  V. Granier,et al.  Ultraviolet laser ablation of polymers: Yield and spatial distribution of products deposition , 1990 .

[13]  M. Allmen.  Laser-beam interactions with materials , 1987 .

[14]  P. Dyer,et al.  Ultraviolet-laser-induced ablation of poly(ethylene terephthalate) , 1991 .

[15]  T. Damm,et al.  Picosecond UV Excimer Laser Ablation of LiNbO3 , 1990 .