A 3D IC structure includes multiple die layers, such as a top die layer and a bottom die layer. The top die layer and/or the bottom die layer each includes devices such as computing units, Analog-to-Digital converters, analog circuits, RF circuits, logic circuits, sensors, Input/Output devices, and/or memory devices. The devices on the first and the second die layers are laterally surrounded by, or adjacent, vertical interconnect structures (VIS).