An integrated semiconductor device is provided. The integrated semiconductor device includes a first semiconductor structure having a first IC, and a second semiconductor structure stacked above the first semiconductor structure and having a second IC. The second semiconductor structure has a first surface facing the first semiconductor structure and a second surface facing away from the first semiconductor structure. The integrated semiconductor device also includes a thermal dissipation structure having a first portion partially through the first IC and a second portion fully through the second semiconductor structure and exposed at the second surface of the second semiconductor structure. The second portion may be outside of the second IC.