A new analytical model for the thermal resistance, temperature profile, and heat flow of deep-trench isolated (DTI) transistors is presented by taking the finite heat flow through
the trenches into account. The new model is able to distinguish between the different contributions to the thermal resistance of the DTI structure and allows identification of the most dominant component. A detailed analysis of the substrate contribution shows that the substrate thermal resistance is overestimated in existing models. Results are compared with experimental data as well as numerical simulations and show a good agreement. The model can be used for process optimization and in a circuit simulator.