Construction of a Broad-Based Experimental and Computational Test Capability for High Power Wide Bandgap Semiconductor Devices

In this paper, the authors will discuss the development and implementation of a test stand to assess the impact of temperature on the performance of commercial X-band gallium nitride (GaN) on silicon carbide (SiC) high electron mobility transistors (HEMTs) designed for radio frequency (RF) communications platforms. The devices are tested under a range of operating temperatures and under a range of electrical operating conditions of variable gate and source-drain voltages to assess the impact of temperature on core operational parameters of the device such as channel resistance and transconductance. This test capability includes infrared thermography and transient thermal impedance measurements of the device. In addition to the experimental effort, the initial construction of a finite-volume numerical analysis model of the device will be discussed. The focus of these models will be the accurate assessment of device thermal impedance based on assumed thermal loads and eventually the assessment of accumulated thermal stresses at the material interfaces within the device and package structure.