Devices, transistor structures, systems, and techniques are described herein related to coupling backside and frontside metallization layers that are on opposite sides of a device layer. A device includes a transistor having semiconductor structures extending between a source and a drain, and a gate between the source and drain, a bridge via extending between a frontside metallization over the transistor and a backside metallization below the transistor, and a thin insulative liner between the bridge via and components of the transistor.