Ablation of poly(methyl methacrylate) and poly(2-hydroxyethyl methacrylate) by 308, 222 and 193 nm excimer-laser radiation

Data on the ablation of Poly(Methyl MetAcylate) (PMMA) and Poly(2-Hydroxyethyl MetAcylate) (PHEMA) with 0%, 1% and 20% of Ethylene Glycol DiMethAcrylate (EGDMA) as crosslinking monomer by 193, 222 and 308 nm laser radiation are presented. Direct photoetching of PMMA at 308 nm is demonstrated for laser fluences ranging from 2 to 18 J/cm2. The ablation rate of PHEMA is lower than the corresponding to PMMA and decreases when the amount of EGDMA increases. The determination of the absorbed energy density required to initiate significant ablation suggests that the photoetching mechanism is similar for all the polymers studied and is a function of the irradiation wavelength. The Beer-Lambert law, the Srinivasan, Smrtic and Babu (SSB) theory and the kinetic model of the moving interface are used to analyze the experimental results. It is shown that only the moving interface theory fits well the etch rate for all the selected polymers at the three radiation wavelengths.

[1]  S. Cain A photothermal model for polymer ablation : chemical modification , 1993 .

[2]  G. Mahan,et al.  Theory of polymer ablation , 1988 .

[3]  T. Damm,et al.  Incubation/ablation patterning of polymer surfaces with sub-μm edge definition for optical storage devices , 1992 .

[4]  T. Chuang,et al.  Laser induced photodissociation and desorption. I. CH2I2 adsorbed on Al2O3 , 1989 .

[5]  I. Constable,et al.  Quantitative measurement of the ablation rate of poly(methyl methacrylate) with 193‐nm excimer laser radiation , 1990 .

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

[7]  R. Srinivasan,et al.  Ultraviolet laser ablation and etching of polymethyl methacrylate sensitized with an organic dopant , 1988 .

[8]  P. H. Key,et al.  Direct etching of polymeric materials using a XeCl laser , 1983 .

[9]  S. Babu,et al.  Excimer laser induced ablation of polyetheretherketone, polyimide, and polytetrafluoroethylene , 1992 .

[10]  S. Babu,et al.  Excimer laser ablation of polyimide‐doped poly(tetrafluoroethylene) at 248 and 308 nm , 1993 .

[11]  S. Babu,et al.  Excimer laser etching of polymers , 1986 .

[12]  R. Srinivasan,et al.  Ablative photodecomposition: action of far-ultraviolet (193 nm) laser radiation on poly(ethylene terephthalate) films , 1982 .

[13]  Stephen R. Cain,et al.  Photothermal description of polymer ablation: Absorption behavior and degradation time scales , 1992 .

[14]  S. Lazare,et al.  Empirical photoablation rate model exemplified with the etching of polyphenylquinoxaline , 1989 .

[15]  M. Stuke,et al.  PHOTOFRAGMENTATION PATHWAYS OF A PMMA MODEL-COMPOUND UNDER UV EXCIMER LASER ABLATION CONDITIONS , 1990 .

[16]  R. Sauerbrey,et al.  Pulsed ultraviolet laser ablation , 1993 .

[17]  Bodil Braren,et al.  Photochemical cleavage of a polymeric solid: details of the ultraviolet laser ablation of poly(methyl methacrylate) at 193 nm and 248 nm , 1986 .

[18]  Bodil Braren,et al.  Ablation and etching of polymethylmethacrylate by very short (160 fs) ultraviolet (308 nm) laser pulses , 1987 .

[19]  S. Namba,et al.  Effective deep ultraviolet photoetching of polymethyl methacrylate by an excimer laser , 1982 .

[20]  Bodil Braren,et al.  Nature of ‘‘incubation pulses’’ in the ultraviolet laser ablation of polymethyl methacrylate , 1990 .

[21]  S. Lazare,et al.  Excimer laser light induced ablation and reactions at polymer surfaces as measured with a quartz-crystal microbalance , 1988 .

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

[23]  M. Stuke,et al.  Femtosecond uv excimer laser ablation , 1987 .

[24]  J. Brannon,et al.  KrF-laser ablation of polyurethane , 1993 .

[25]  N. Peppas Hydrogels in Medicine and Pharmacy , 1987 .

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

[27]  D. Seeger,et al.  Low temperature UV laser etching of PMMA: On the mechanism of ablative photodecomposition (APD) , 1986 .

[28]  H. Hiraoka,et al.  Laser-photoetching characteristics of polymers with dopants , 1988 .

[29]  Bodil Braren,et al.  Ablative photodecomposition of polymer films by pulsed far‐ultraviolet (193 nm) laser radiation: Dependence of etch depth on experimental conditions , 1984 .

[30]  N. Furzikov Approximate theory of highly absorbing polymer ablation by nanosecond laser pulses , 1990 .

[31]  James Hammond Brannon,et al.  Threshold behavior in polyimide photoablation: Single-shot rate measurements and surface-temperature modeling , 1993 .

[32]  C. Klauber,et al.  Interaction between Poly(2- hydroxyethyl methacrylate) and High Energy Excimer Laser Radiation† , 1992 .

[33]  R. Sauerbrey,et al.  Theory for the etching of organic materials by ultraviolet laser pulses , 1989 .

[34]  R. Srinivasan,et al.  Theory of etching of polymers by far-ultraviolet high-intensity pulsed laser- and long-term irradiation , 1984 .

[35]  M. Stuke,et al.  UV-excimer-laser ablation of polymethylmethacrylate at 248 nm: Characterization of incubation sites with Fourier transform IR- and UV-Spectroscopy , 1989 .

[36]  T. Keyes,et al.  Theory of photoablation and its implications for laser phototherapy , 1985 .

[37]  M. Späth,et al.  Time resolved dynamics of subpicosecond laser ablation. , 1993 .

[38]  J. Brannon,et al.  Excimer laser etching of polyimide , 1985 .

[39]  Rod S. Taylor,et al.  Comparison of theoretical models of laser ablation of polyimide with experimental results , 1990 .

[40]  L. Kalontarov Mechanism of laser-induced ablation of polymeric solids , 1991 .