We present a set of design tools for three dimensional (3D) mixed mode placement (MMP). The hierarchical 3D MMP design tool is composed of a hierarchical clustering package, a new 3D floorplanning tool, route planning tool, and 2D global/detailed placement tools. We have analyzed the performance of 3D circuit using these tools. It is shown that total wirelength could be reduced by 25% to 43% compared with traditional 2D design using two to four stacked dies. By incorporating thermal management and analysis, we also investigate the thermal scalability of 3D integration