Normally Off Vertical 3-D GaN Nanowire MOSFETs With Inverted p -GaN Channel

This is the authors' abstract. We don't add key points for this paper.

This paper reports on the normally off GaN vertical MOSFETs based on nanowires (NWs) with an inverted p-GaN channel and a wrap-around-gate structure for the first time. Both inductively coupled plasma dry reactive-ion etching and wet-chemical etching were employed to fabricate the vertically aligned GaN NWs from epitaxial thin films with a specified doping profile. During the wet etching, the influence of p-doping on the NW morphology was investigated, and the results could be explained by the proposed model. In comparison with other c-axis NW transistors, an enhancement-mode (E-mode) operation with a superior threshold voltage (Vth) of 2.5 V has been reached in the fabricated GaN MOSFETs. Furthermore, a high driving-current density of 101 kA/cm2as well as a high ON-/OFF-current ratio of 109was obtained in the NWs, predicting a potential approach toward future GaN electronics with vertical and smart architecture.