Characterization of Copper Complex Paste: Manufacture of Thin Cu-Seed Films on Alumina Substrates

The fabrication process of pure Cu films on an alumina substrate using a copper complex paste was evaluated. After vigorous milling for 7 h, copper complexes (copper(II) formate and pure Cu) with an average particle size of 312 nm were formed. A printed pattern was prepared with a paste containing the particles and a pure Cu film was formed by annealing at 250 °C for 30 min under nitrogen atmosphere. After removing the upper part of the film, a homogenous Cu film with a thickness of 424 nm was observed on the substrate. The film demonstrated excellent adhesion properties and had an low electrical resistivity of 4.38 μΩ cm. Hence, the film can be used as a seed for additional Cu plating. Graphical Abstract