Investigation of Normally-Off p-GaN/AlGaN/GaN HEMTs Using a Self-Terminating Etching Technique with Multi-Finger Architecture Modulation for High Power Application.

Normally-off p-gallium nitride (GaN) high electron mobility transistor (HEMT) devices with multi-finger layout were successfully fabricated by use of a self-terminating etching technique with Cl2/BCl3/SF6-mixed gas plasma. This etching technique features accurate etching depth control and low surface plasma damage. Several devices with different gate widths and number of fingers were fabricated to investigate the effect on output current density. We then realized a high current enhancement-mode p-GaN HEMT device with a total gate width of 60 mm that exhibits a threshold voltage of 2.2 V and high drain current of 6.7 A.