Laser-assisted writing of copper films through Nd:YAG laser radiation

Abstract

The use of a laser-assisted process for direct writing of copper films and coatings has significant potential for several applications within the electronics industry. Experiments were conducted using a pulsed Nd:YAG (1064 nm) laser to irradiate a metallo-organic precursor film that had been predeposited onto glass and FR-4 substrates. Parameters that were investigated included irradiation wavelength, pulsing conditions, precursor thickness, and the use of inert and active shielding gas. Scanning electron microscopy, energy dispersive x-ray spectroscopy, and electrical resistivity measurements were used to characterize the processed specimens. Initial results of these experiments indicated that Nd:YAG irradiation resulted in decomposition of the precursor and deposition of copper; although, the crystalline deposits contained varying levels of oxide. It is believed that the decomposition mechanism is pyrolytic.The use of a laser-assisted process for direct writing of copper films and coatings has significant potential for several applications within the electronics industry. Experiments were conducted using a pulsed Nd:YAG (1064 nm) laser to irradiate a metallo-organic precursor film that had been predeposited onto glass and FR-4 substrates. Parameters that were investigated included irradiation wavelength, pulsing conditions, precursor thickness, and the use of inert and active shielding gas. Scanning electron microscopy, energy dispersive x-ray spectroscopy, and electrical resistivity measurements were used to characterize the processed specimens. Initial results of these experiments indicated that Nd:YAG irradiation resulted in decomposition of the precursor and deposition of copper; although, the crystalline deposits contained varying levels of oxide. It is believed that the decomposition mechanism is pyrolytic.