@misc{YazdaniZervosBeleniotisetal., author = {Yazdani, Hossein and Zervos, Christos and Beleniotis, Petros and Brusaterra, Enrico and Hilt, Oliver and Rudolph, Matthias and W{\"u}rfl, Joachim}, title = {Importance of Scaling in RF GaN HEMTs for Reduction of Surface Traps-Induced Drain Lag}, series = {Physica Status Solidi (a)}, journal = {Physica Status Solidi (a)}, publisher = {Wiley}, issn = {1862-6300}, doi = {10.1002/pssa.202300885}, pages = {1 -- 8}, abstract = {Drain lag is a well-known phenomenon that leads to radio frequency performance degradation in AlGaN/GaN high-electron-mobility transistors. Herein, it is demonstrated that a reduction of the gate-to-drain distance (Lgd) from 2.0 to 0.5 μm results in 7\% reduction in the current collapse. This improvement is attributed to a decrease in surface trapping, which, in this case, is found to have a greater impact on current collapse than relatively slow traps in the buffer layer. To support this argument, TCAD simulations are conducted. Load-pull analysis confirms that scaling the devices to Lgd = 0.5 μm provides 15\% better output power density at 10 GHz than Lgd = 2.0 μm. Additionally, a new passivation layer for reduced surface traps exhibits a 20 to 30\% higher output power density and at least a 10\% improvement in power-added efficiency at 20 GHz on a nominally identical GaN-on-semi-insulating SiC epi-wafer.}, language = {en} } @misc{YazdaniBeleniotisBrunneretal., author = {Yazdani, Hossein and Beleniotis, Petros and Brunner, Frank and Ostermay, Ina and W{\"u}rfl, Joachim and Rudolph, Matthias and Heinrich, Wolfgang and Hilt, Oliver}, title = {K/Ka-Band-GaN-High-Electron-Mobility Transistors Technology with 700 mS mm-1 Extrinsic Transconductance}, series = {Physica Status Solidi}, journal = {Physica Status Solidi}, doi = {10.1002/pssa.202400592}, pages = {8}, language = {en} }