Analysis of the Thermal Behavior of Trench-Isolated Bipolar Transistors Fabricated on SOI Substrates

摘要

The thermal behavior of trench-isolated bipolar transistors fabricated on SOI (Silicon-On-Insulator) substrates is analyzed. Detailed 3-D numerical simulations are performed to investigate the impact of all technological parameters of interest. A new analytical model to evaluate the temperature field is proposed, which is based on the reduction of the domain under analysis to a silicon rectangular parallelepiped with convective boundary conditions at lateral and bottom faces. An extensive comparison with numerical results proves that the model is extremely accurate over the whole range of parameters, and can be adopted for a fast evaluation of the thermal resistance of a trench SOI device as well as of the temperature gradients within the silicon island surrounded by trenches and buried oxide.