Scaling Effect in Gate-Recessed AlGaN/GaN Fin-Nanochannel Array MOSHEMTs

In this study, to compare the performance of planar, fin-submicron, and fin-nanochannel array-structured AlGaN/GaN metal-oxide-semiconductor high-electron-mobility transistors (MOSHEMTs), the scaling effect of fin-channels was investigated by decreasing the nanochannel width to 50 nm using an electron-beam lithography system. The photoelectrochemical oxide method was used to directly oxidize the AlGaN layer into a gate oxide layer and to passivate the fin-nanochannel array. Consequently, the low-noise performance and Hooge's coefficient were improved in AlGaN/GaN fin-nanochannel MOSHEMTs with narrower fin-channels. The improvement was attributed to the effective passivation and the screening effect of trapping probability. Moreover, owing to the improvement in gate control capability caused by the fin structure and the improvement in heat dissipation caused by the lateral heat flow, the direct current and high-frequency performances were improved by using a narrower fin-channel in AlGaN/GaN fin-nanochannel array MOSHEMTs.