Impact of Gate Length Scaling on DC and RF Performance in AlGaN/GaN HEMTs

This study systematically analyzes the impact of gate length scaling on the DC and RF performance of AlGaN/GaN High Electron Mobility Transistors (HEMTs). By examining transfer characteristics for various gate lengths, we observed significant changes in threshold voltage <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(V_{TH})$</tex>, subthreshold swing (SS), and drain-induced barrier lowering (DIBL), particularly when the gate length is below 0.1 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu \mathrm{m}$</tex>. These changes indicate the onset of strong short-channel effects (SCE). Although strong SCE occurs at a gate length of 0.1 <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mu\mathrm{m}$</tex>, the highest cutoff frequency is achieved at this gate length. Our findings provide optimal design guidelines for scaled <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\mathbf{GaN}$</tex> HEMTs and contribute to the development of advanced RF devices.