A stacked device is provided. The stacked device includes a reduced height active device layer, and a plurality of lower source/drain regions in the reduced height active device layer. The stacked device further includes a lower interlayer dielectric (ILD) layer on the plurality of lower source/drain regions, and a conductive trench spacer in the lower interlayer dielectric (ILD) layer, wherein the conductive trench spacer is adjacent to one of the plurality of lower source/drain regions. The stacked device further includes a top active device layer adjacent to the lower interlayer dielectric (ILD) layer, and an upper source/drain section in the top active device layer. The stacked device further includes a shared contact in electrical connection with the upper source/drain section, the conductive trench spacer, and the one of the plurality of lower source/drain regions.