Effect of High Temperature on the Performanceof AlGaN/GaN T-Gate High-Electron MobilityTransistors With140-nm Gate Length

High temperature (HT) electronics applica-tions will require the development of a broad range ofdevices made using different materials. Among thesedevices, high-electron mobility transistors (HEMTs) madewith GaN and its alloys are attractive for high-power radiofrequency (RF) applications. In this manuscript, we testedAlGaN/GaN HEMT devices having similar to 140-nm gate length atdifferent temperatures up to 500 degrees C. Devices were fab-ricated using Air Force Research Laboratory's (AFRL's)140-nmT-gate process technology. The performancedegradation measured in different devices was analyzed byconsidering changes in different device parameters and byusing appropriate device physics. Cross-sectional materi-als characterization using scanning transmission electronmicroscopy (STEM) and electron energy loss spectroscopy(EELS) was performed to understand the origin of perfor-mance degradation. This understanding will allow us todesign a sub-mu m GaN-based process technology compat-ible with HT RF applications