Thermal simulation of heterogeneous GaN/ InP/silicon 3DIC stacks

Integration of materials such as GaN, InP, SiGe, and Si is a natural extension of the 3D-IC perspective and provides a unique solution for high performance circuits. In this approach, application of a component is no longer dependent on semiconductor material selection. In this paper, preliminary results are presented which examine the thermal performance of the technology. A thermal analysis prototype solution in Mentor Graphics^™ Calibre^® provides surface heat maps based on IC layout, material property, and geometric configuration files. Chiplets are connected by heterogeneous interconnect (HIC). Differences in thermal performance of GaN and InP chiplets are explored by varying the number of HICs. Two methods for building up the model of a test chip are compared. One method uses custom scripts to place discrete blocks in the model to represent HICs, while the other uses thermal material properties extracted from the layout. Measurements presented confirm simulated results.