A novel method to determine the conduction channel effective width of split-gate AlGaN/GaN high electron mobility transistors

In this study, split-gate AlGaN/GaN high electron mobility transistors (HEMTs) with a hollow-gate structure were designed. The measurement and analysis of the samples showed that the influence of polarization Coulomb field scattering could be greatly weakened without changing the conduction channel effective width (Weff) by using the hollow-gate structure. Therefore, a general experimental method for quantitatively determining Weff was obtained. In addition, the channel conduction status of the samples was studied, and the primary mechanism affecting the shape and size of the conduction channel was identified. During this process, the conduction channel shape that closely aligns with the experimental results was provided, and a theoretical method for approximately determining Weff was also obtained. This research has guiding value for the quantitative solution of transport-related parameters in split-gate AlGaN/GaN HEMTs.