Impact of Source Field Plate in GaN-Based Fin-Gated Multichannel MOSHEMTs

To investigate the impact of the source field plate in gallium nitride (GaN)-based fin-gated multichannel metal-oxide-semiconductor high-electron mobility transistors (MOSHEMTs), devices with different multichannel widths and different source field lengths were fabricated. Compared to the characteristics of the GaN-based fin-gated multichannel MOSHEMTs without and with a source field plate, the addition of the source field plate did not affect their saturation drain-source current, transconductance, threshold voltage, subthreshold swing, leakage current, and low-frequency noise. However, using a source field plate in the various GaN-based fin-gated multichannel MOSHEMTs could enhance their respective breakdown voltage. Furthermore, the associated breakdown voltage was influenced by the length of the source field plate. In various GaN-based fin-gated multichannel MOSHEMTs with a drain-source distance of 10 μm, devices with a source field plate length of 8 μm exhibited the highest breakdown voltage. Compared with the breakdown voltage of 735 V for the GaN-based 80-nm-wide fin-gated multichannel MOSHEMTs without a source field plate, the breakdown voltage was improved to 842 V by using a source field plate of 8 μm length.