Characteristics of GaN-Based Nanowire Gate-All-Around (GAA) Transistors.

We investigate the DC, , and pulse performances in GaN-based nanowire gate-all-around (GAA) transistors with two kinds of geometry: one is AlGaN/GaN heterostructure with two dimensional electron gas (2DEG) channel and the other is only GaN layer without 2DEG channel. From and curves, the fabricated GaN nanowire GAA transistor with AlGaN layer clearly exhibits normally-on operation with negative threshold voltage () due to the existence of 2DEG channel on the trapezoidal shaped GaN nanowire. On the other hand, the GaN nanowire GAA transistor without AlGaN layer presents a positive (normally-off operation) due to the absent of 2DEG channel on the triangle shaped GaN nanowire.