EXPERIMENTAL INVESTIGATION OF THE TEMPERATURE-DEPENDENCE OF GAAS-FET EQUIVALENT-CIRCUITS

Accurate 13-element temperature-dependent RF equivalent circuits have been extracted from on-wafer S-parameter measurements of ion implanted and epitaxially grown recess-gate MESFET's and HEMT's at many biases for temperatures from -70 to +110-degrees-C. The variations in each equivalent circuit element are expressed by a linear function of temperature. The temperature coefficients are bias- and technology-dependent. These data can be used to predict RF circuit performance variations with temperature. We use it to deduce the temperature dependence of physical factors such as electron mobilities and saturated velocities and the Schottky-barrier height.