Direct Deposition of Metal Film Patterns Using Nitrogen Laser

Abstract
Rhenium, gold and platinum film micropatterns were obtained by the LCVD method on the surface of silicon and glass substrates from vapors of Re₂(CO)₁₀, (CH₃)₂Au(dpm), Pt(hfa)₂, respectively. The heated reaction chamber at atmospheric pressure with a flow of an inert gas-carrier was used. The high marginal sharpness and the thickness uniformity of deposited films was provided by the use of a powerful nanosecond pulse nitrogen laser (λ = 337 nm), a projective system for delineation of the irradiation zone and by laser beam microscanning in the limits of the projective mask window. The metal pattern replicating the configuration of the projective mask window with a uniform 0.1-1 µm thickness was formed during 1-10 s. The writing rate of the straight metal lines was limited by the size of the irradiation zone and by the pulse repetition frequency and made of 150 µm/s. The smooth Re films were obtained with a good adhesion to the substrate and a surface resistivity of about Ω/square. The films of Au and Pt were deposited as layers of microdrops whose coupling with one another and with the contact ground determined the film resistivity. The melting of Au and Pt films occurs during the laser-induced deposition process and influences the film growth dynamics and the film-to-substrate adhesion.