Electron microscopy studies of ion implanted silicon for seeding electroless copper films

The feasibility of ion implantation induced electroless copper plating as an effective technique for micro electromechanical systems fabrication was explored by our group recently. This paper aims at investigating such implanted surfaces in order to understand the mechanism assisting the plating. Si was implanted with Pd+ ions at an ion energy of 19 keV in a metal vapour vacuum arc (MEVVA) implanter. The implantation dose ranged between 7×1014 and 2×1017 ions/cm2. The substrates were characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). TEM studies on these substrates indicated that implanted ions tend to form metallic clusters or agglomerates in the substrate. The electroless films nucleate at these clusters. An attempt was made to establish a relationship between implantation dose and cluster size. The topology of the electroless plated films was examined under SEM and the results are discussed in detail.