Abstract: The specification describes interconnection techniques for interconnecting large arrays of micromechanical devices on a silicon platform. Interconnections are routed through vias extending through the thickness of the substrate. The vias are formed by etching holes through the silicon wafer, depositing an insulating layer on the sidewalls of the holes, depositing a barrier layer on the insulating layer, electrolytically depositing a metal selected from the group consisting of copper and nickel to form via plugs in the holes, and depositing another barrier layer over the via plugs. It is found that electrolytic deposition will successfully plug the holes even when the aspect ratio of the through holes is greater than four and the hole diameter less than 100 microns.

Abstract: A process for fabricating a semiconductor device with copper interconnects is disclosed. In the process of the present invention, a layer of dielectric material is formed on a substrate. A barrier layer to prevent copper diffusion is then deposited over the entire surface of the substrate. A dual copper layer is formed on the barrier layer. The dual layer has a copper layer deposited by PVD and a copper layer deposited by electroplating. The copper layers are adjacent to each other. The ratio of the thickness (X) of the electroplated, layer to the thickness of the PVD layer (Y) is about 1:0.5 to about 1:2. The thickness of the electroplated layer is at least about 3 &mgr;m. The thickness of the PVD copper layer is at least about 100 nm. The thickness of the two layers is selected to effect recrystallization of the electroplated copper from a small grain size (0.1 &mgr;m to 0.2 &mgr;m) to a large grain size (1 &mgr;m or greater).

Abstract: A process for fabricating a semiconductor device with copper interconnects is disclosed. In the process of the present invention, a layer of dielectric material is formed on a substrate. At least one recess is formed in the layer of dielectric material. Barrier layers and seed layers for electroplating are then deposited over the entire surface of the substrate. The recess is then filled with copper by electroplating copper over the surface of the substrate. The electroplated copper has an average grain size of about 0.1 &mgr;m to about 0.2 &mgr;m immediately after deposition. The substrate is then annealed to increase the grain size of the copper and to provide a grain structure that is stable over time at ambient conditions and during subsequent processing. After annealing, the average grain size of the copper is at least about 1 &mgr;m in at least one dimension. The copper that is electroplated on the dielectric layer is then removed using an expedient such as chemical mechanical polishing.