Thermal Sensitivity of Microwave Pseudomorphic High-Electron-Mobility Transistor Performance: Pre and Post Multilayer Technology

摘要

Herein, the temperature dependence of direct current (DC) and scatteringparameters of GaAs pseudomorphic high-electron-mobility transistors (pHEMTs)before and after back-end-of-line process (multilayer technology) by evaluatingcorresponding equivalent-circuit models is reported on. The change of the relativesensitivity of the microwave performance with ambient temperature isevaluated using scattering parameter measurements and the correspondingequivalent-circuit models. The devices studied are two pHEMTs with the same200 μm gate width but manufactured using pre- and post-multilayer technology.The investigation is conducted under both cooled and heated conditions, throughtemperature variations from -25 to 125 °C. Although the thermal impact highlydepends on the selected operating condition, the bias point is chosen to allow fora fair comparison between the transistor fabricated before and after multilayertechnologies to the maximum. Similar patterns of thermal sensitivities areobserved for the pre and post multilayer-manufactured devices but in the case ofthe multilayer device, the temperature effect is more pronounced.