A three-dimensional integrated circuit includes a first die structure having a first geometry. The first die structure includes a first region that operates with a first power density and a second region that operates with a second power density. The first power density is less than the second power density. The three-dimensional integrated circuit includes a second die structure having a second geometry. A stacked portion of the second die structure is aligned with the first region. The three-dimensional integrated circuit includes an additional die structure stacked with the first die structure and the second die structure. The additional die structure has the first geometry or the second geometry.