A Simple Extraction Method of Thermal Resistance in Multifinger GaAs HBT

摘要

A novel extraction method to estimate the thermal resistance ( of a multifinger GaAs heterojunction bipolar transistor (HBT) device is presented based on the simplified Fourier’s law. By calculating the thermal coupling resistance between the fingers on top of the self-heating thermal resistance, the values of of multifinger devices for various dimensions are accurately calculated while maintaining the simplicity of calculation. To verify the idea, the proposed method is compared with the measurement-based method as well as the analytic methods, such as the finite-element method and the solution of 3-D Laplace’s equation. For four-finger HBT devices, the extracted results showed good agreements with the analytic methods within an error of 9% and the measurement-based results with a deviation of 7.4%, thus convincing the usefulness of the proposed method.