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 (g_m) ranging from ~0 to ~8 V at V_D = 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 L_GD of 17 μm exhibited excellent OFF-state characteristic with subthreshold swing of ~58 mV/decade, low OFF-state leakage current of ~10^-12 A, and breakdown voltage of ~400 V at V_G = -9 V.