Microstructure, adhesion strength and thermal conductivity of AlN/(Ti, W)/Cu substrate system

Abstract

Abstract AlN/(Ti, W)/Cu substrates were successfully fabricated by the combination of magnetron sputtering and electroless copper plating, exhibited layered distribution without obvious defects or delamination. The adhesion film in AlN/Ti/Cu was composed of TiN, Al, and Ti crystallites due to the reaction between the sputtered Ti layer and the AlN substrate, while in AlN/W/Cu was α-W and β-W crystallites with a mixed distribution but a thin W-rich amorphous layer at the interface towards Cu contact. In AlN/TiW/Cu was W-rich TixW1−x and α-Ti with the interlayer distribution. The scratch failure of the AlN/(Ti, W)/Cu substrates included the peeling of the Cu plating layer and adhesion film. The nanoscale hard phase layered combination of the adhesion film in AlN/TiW/Cu exhibited better peeling resistance, resulting in the most prominent adhesion strength among the substrate system. The existence of an amorphous layer in AlN/W/Cu led to the lower thermal conductivity. AlN/TiW/Cu substrate showed good comprehensive properties including adhesion strength and thermal conductivity.