Electro-thermal design of multilayer structure integrated devices through the solution to the non-linear 3-D heat flow equation

In this chapter an analytical model to optimize the thermal and electrical layout for multilayer structure electronic devices is reviewed. The model is based on the solution to the non-linear 3-D heat equation. The thermal solution is achieved by the Kirchhoff transform and the 2-D Fourier transform. The electro-thermal feedback is implemented by calculating the device current at the actual channel temperature. The model is general and can be easily applied to a large variety of integrated devices, provided that their structure can be represented as an arbitrary number of superimposed layers with a 2-D embedded thermal source, so as to include the effect of the package. This subject is very important for device designers, provided that the algorithm is reliable and not too difficult to realize practically. Moreover the model is independent on the specific physical properties of the layers, hence GaAs FETs, HBT and HEMTs as well as Silicon and Silicon-On-Insulator MOSFETs and heterostructure LASERs can be analysed.