Modeling of MMIC devices for determining MMIC channel temperatures during life tests

Several analytical techniques were examined for predicting GaAs MMIC (monolithic microwave integrated circuit) junction temperatures to support reliability life tests. Series solution, finite difference, finite element, and boundary element methods were compared using a simple MMIC structure, and the boundary element method was found to be better for predicting MMIC junction temperatures. The series solution method, although it cannot model the plating layers on top of the device, was found to be quite useful for performing preliminary analyses. FETs on several MMIC devices were analyzed using the boundary element method. The thermal effects of several physical features and modeling assumptions were investigated. The thermal model predictions were compared with infrared imager and liquid crystal experimental data