Analytical Electrothermal Modelling of Multilayer Structure Electronic Devices

In this paper we present an analytical model to optimize the thermal and electrical layout for multilayer structure electronic devices through 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 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. Moreover it 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. The proposed model has been applied to a multifinger GaAs FET and to a power Si/SiGe Heterojunction Bipolar Transistor.