Abstract
Demand for metallized polymer films for use in various electronics applications is growing rapidly. Polyimide film has been widely used up to now for such applications as a low-k substrate due to its chemical and thermal stability, and its excellent dielectric properties. Here we report on the use of ion-doped precursors for fabrication of metallic patterns on a polyimide substrate. The process relies on the following steps to enable the fabrication of metallic patterns with a ca. 30 μm line width. First, the surface of the polyimide is modified by an alkaline treatment, then doped with metallic ions. Next, coating and photopatterning of PMMA resist is followed by reduction of the doped ions using aqueous sodium tetrahydroborate. The nanogranular structures are fabricated at the metal/polymer interface after the reduction treatment, which can contribute to relatively high adhesion of the deposited metal thin films on the polyimide substrate. This approach is an etching-free process and provides an effective methodology toward lower-cost and higher-throughput microfabrication.
