Design and analysis of vertical-channel gallium nitride (GaN) junctionless nanowire transistors (JNT).

Vertical-channel gallium nitride (GaN) junctionless nanowire transistor (JNT) has been designed and characterized by technology computer-aided design (TCAD) simulations. Various characteristics such as wide bandgap, strong polariztion field, and high electron velocity make GaN one of the attractive materials in advanced electronics in recent times. Nanowire-structured GaN can be applicable to various transistors for enhanced electrical performances by its geometrical feature. In this paper, we analyze the direct-current (DC) characteristics depending on various channel doping concentrations (N(ch)) and nanowire radii (R(NW)). Furthermore, the radio-frequency (RF) characteristics under optimized conditions are extracted by small-signal equivalent circuit modeling. For the optimally designed vertical GaN JNT demonstrated on-state current (I(on)) of 345 μA/μm and off-state current (I(off)) of 3.7 x 10(-18) A/μm with a threshold voltage (V(t)) of 0.22 V, and subthreshold swing (S) of 68 mV/dec. Besides, f(T) and f(max) under different operating conditions (gate voltage, V(GS)) have been obtained.