Triazene polymers designed for excimer laser ablation

Wiley - Tập 206 Số 1 - Trang 97-110 - 1993
Thomas Lippert1, Alexander Wokaun1, Juergen Stebani2, Oskar Nuyken2, J. Ihlemann3
1Physical Chemistry II, University of Bayreuth, D‐W‐8580 Bayreuth, Germany,
2Macromolecular Chemistry I, University of Bayreuth, D-W-8580 Bayreuth, Germany,
3Laser‐Laboratorium Göttingen, D‐W‐3400 Göttingen, Germany

Tóm tắt

AbstractThe excimer laser‐induced ablation of triazene polymers at a wavelength of 308 nm has been investigated as a function of laser fluence deposited on the surface in one or several pulses. PMMA, which as a homopolymer can not be ablated at 308 nm, has been sensitized for ablation at this wavelength by synthesizing a copolymer in which 0.3 mol‐% of the side chains contain the triazene functional groups. The high ablated depths per pulse achieved in this manner are similar to the ones observed upon physical doping of PMMA with monomeric triazene compounds. In an alternative approach, the triazene functional group is introduced once (polymer TP 1) or twice (TP 2) into each repeating unit of the polymer backbone by a polycondensation reaction. Irradiation of TP 1 gives rise to ill‐defined ablation profiles with sloping wall. In contrast, clean circular ablation profiles are obtained with polymer TP 2, which are characterized by circular contours, steep edges, and flat bottoms of the ablated craters. The origins of these differences are investigated. A comparative study of excimer laser ablation of TP 2 at 248 and 308 nm shows that the latter wavelength is more effective; the plateau value of the ablated depth per pulse corresponds to ≈ 1 μm at 248 nm and ≈ 3 μm at 308 nm. This dependence is attributed to the photolysis behaviour of the triazene compounds: nitrogen released upon photolytic bond cleavage acts as a driving gas which promotes the ablation. As a consequence, no ‘incubation pulses’ are required for triazene polymer ablation in the investigated fluence range.

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Tài liệu tham khảo

10.1063/1.93108

10.1063/1.93601

G. E.Wolbold E.Roth W.Stoeffler J. R.Lankard Proc. Laserion Conference Munich 12.–14. 6. 1991 p. 75;

10.1007/BF00324201

10.1364/JOSAB.3.000785

10.1016/0169-4332(90)90156-T

T.Lippert J.Dauth J.Stebani O.Nuyken A.Wokaun J.Ihlemann to be published 1993

10.1007/BF00616301

10.1103/PhysRevLett.58.2142

10.1063/1.336728

10.1080/00268979200102511

10.1002/bbpc.19830871214

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Wiley

Tập 206 Số 1

97-110

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