A process and resultant article of manufacture made by such process comprises forming through vias needed to connect a bottom device layer in a bottom silicon wafer to the one in the top device layer in a top silicon wafer comprising a silicon-on-insulator (SOI) wafer. Through vias are disposed in such a way that they extend from the middle of the line (MOL) interconnect of the top wafer to the buried oxide (BOX) layer of the SOI wafer with appropriate insulation provided to isolate them from the SOI device layer.