Formation of Cu electrical circuit by simplified damascene process based on UV-assisted thermal imprinting

This study explored a simplified micro-scale Cu damascene process based on UV-assisted thermal imprinting of SU-8 to investigate its process merits and potential defects that may occur during and after processing. For comparative study, arbitrary electrical circuits composed of Cu wiring structures with widths ranging from 10@mm to 1mm were developed in SU-8/Si patterned by UV-assisted thermal imprinting and in oxidized Si samples prepared by reactive ion etching (RIE) followed by thermal oxidation. The imprint-based approach could lower process cycles, equipment cost, and etching gas use, whereas it induced a higher residual stress and more delamination defects. The process studied here are expected to be applied to fabricate micro-scale Cu structures, such as coils, antennas, electrical circuits, and wiring and connecting lines if further enhancements of the adhesion ability between layers and the design of pattern fields in a mold are accomplished.