Electrical and Thermal Cosimulation of GaAs Interconnects

It is well known that the poor thermal conductivity of GaAs adversely affects the electrical performance of GaAs circuits. Although they interact, the electrical and thermal circuits are simulated using separate software simulation packages. If the circuits are cosimulated on the same package, then the electrical and thermal circuits can interactively determine accurate information for the temperature-dependent variables of the electrical circuit. This paper demonstrates a method of electrical and thermal cosimulation of GaAs interconnects. To illustrate, the method is implemented on a meander line deposited on a GaAs epitaxial substrate. Each horizontal and vertical section of the meander is viewed as an individual heat source cell. An iterative procedure solves for the temperature of each cell and predicts the dc resistance of the line. Using a first-order thermal circuit, simulation shows good agreement with experimental data.