Direct writing of copper micropatterns using near-infrared femtosecond laser-pulse-induced reduction of glyoxylic acid copper complex

Mizue Mizoshiri, Keiko Aoyama, Akira Uetsuki, Tomoji Ohishi

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2 Citations (Scopus)

Abstract

We have fabricated Cu-based micropatterns in an ambient environment using femtosecond laser direct writing to reduce a glyoxylic acid Cu complex spin-coated onto a glass substrate. To do this, we scanned a train of focused femtosecond laser pulses over the complex film in air, following which the non-irradiated complex was removed by rinsing the substrates with ethanol. A minimum line width of 6.1 μm was obtained at a laser-pulse energy of 0.156 nJ and scanning speeds of 500 and 1000 μm/s. This line width is significantly smaller than that obtained in previous work using a CO2 laser. In addition, the lines are electrically conducting. However, the minimum resistivity of the line pattern was 2.43 × 10-6 Ωm, which is ~10 times greater than that of the pattern formed using the CO2 laser. An X-ray diffraction analysis suggests that the balance between reduction and re-oxidation of the glyoxylic acid Cu complex determines the nature of the highly reduced Cu patterns in the ambient air.

Original languageEnglish
Article number401
JournalMicromachines
Volume10
Issue number6
DOIs
Publication statusPublished - 2019 Jun 1

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Keywords

  • Cu micropattern
  • Femtosecond laser
  • Glyoxylic acid Cu complex
  • Laser direct writing
  • Reduction

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Mechanical Engineering
  • Electrical and Electronic Engineering

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