AlGaN/GaN FinFET With Extremely Broad Transconductance by Side-Wall Wet Etch

AlGaN/GaN-based fin-shaped field-effect transistors with very steep side-wall have been fabricated by utilizing electron-beam lithography and subsequent anisotropic side-wall wet etch in tetramethyl ammonium hydroxide solution. The investigate device demonstrated extremely broad transconductance (gm) ranging from ~0 to ~8 V at VD= 10 V, which is essential for high linearity device performance. Pulse measurement showed that the device exhibits negligible gate lag, but still suffers from drain lag. The device with LGDof 17 μm exhibited excellent OFF-state characteristic with subthreshold swing of ~58 mV/decade, low OFF-state leakage current of ~10-12A, and breakdown voltage of ~400 V at VG= -9 V.