AlGaN/GaN high electron mobility transistors with a range of dual metal gate (DMG) lengths have been fabricated and studied. An improvement in transconductance up to 9% has been measured in the DMG devices in comparison to the conventional single metal gate devices. This is attributed to the distribution of the electric field under the gate region as a result of two gate metals. The drain induced barrier lowering is also suppressed using the sub-µm DMG devices, with a drain induced barrier lowering decrease of around 50% due to a potential shielding effect in the two-dimensional electron gas channel.

This is a repository copy of Fabrication of semi-polar (11-22) GaN V-groove MOSFET using wet etching trench opening technique.

An all-GaN integrated cascode device with an output current of 5 A, threshold voltage of +0.65 V and breakdown voltage of 624 V is demonstrated. Compared to the commercial 600 V hybrid GaN plus Si cascode device (TPH3202), the integrated cascode exhibits a significantly reduced delay time when switched at 200 V and 2.7 A. This is attributed to the absence of a Si MOSFET driver, leading to a much smaller input capacitance as indicated by the high voltage capacitance measurements. In addition, the integrated cascode device shows a reduced ringing effect due to monolithic integration. When compared to commercial 600 V standalone GaN devices (GS66502B and GS-065-004), a reduced Miller effect is observed for the integrated cascode when switched under low gate driving current conditions. The results demonstrate the advantages of the cascode device to switch with low gate driving current using cheaper, faster and more efficient gate drivers.