A 3-D thermal simulation tool for integrated devices - Atar

This paper presents a novel three-demensional (3-D) thermal simulation tool for semiconductor integrated devices. The simulator is used to automatical ly generate an accurate 3-D physical model of the device to be simulated fr om layout information. The simulator produces an appropriate mesh of the de vice based on a rectangular block structure. The mesh is automatically crea ted such that a fine mesh Is produced around heat generation regions, but a moderate number of blocks are used for the entire device. This paper first confirms that the simulator produces an accurate solution to the nonlinear differential equation describing the heat flow. Then model generation from three example technologies (silicon trench, GaAs mesa stru ctures, silicon on insulator) is presented. The potential of the simulator to quickly and easily explore the effect of layout and process variations i s illustrated, with the simulation of a two-transistor GaAs power cell as a large example. The program incorporates a transient solver based on a transmission line ma trix (TLM) implementation using a physical extraction of a resistance and c apacitance network. The formulation allows for temperature dependent materi al parameters and a nonuniform time stepping. An example of a full transien t solution of heat flow in a realistic Si trench device is presented.