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An AlGaN/GaN lateral field-effect rectifier with intrinsic ON-state current limiting capability is demonstrated by adding a Schottky contact metal (length of LD) beyond the ohmic contact region at the cathode electrode. The onset of the current limiting function is self-activated when the voltage drop across the two-dimensional gas (2DEG) channel under the Schottky contact reaches the pinch-off voltage of the as-grown AlGaN/GaN heterojunction. With LD=2 µm and a drift region length of 7 µm, the proposed lateral rectifier exhibited an ON-state current that was self-limited at 1.56 kA/cm2, while achieving a reverse breakdown voltage of 347 V at a 1mA/mm leakage current. [ABSTRACT FROM AUTHOR]

A high-voltage normally-off AlGaN/GaN hybrid-gate HEMT (HG-HEMT) with high current-density and low on-resistance on Si substrate is fabricated. The proposed device features a hybrid-gate consisting of a short E-mode gate and a long D-mode gate. In the off-state, the short E-mode gate confirms the normally-off operation, while the D-mode gate can clamp the channel potential at a low drain voltage, which delivers high blocking capability. In the on-state, the short E-mode channel and the D-mode channel providing lower channel resistance facilitate high on-current or low on-resistance. Therefore, the HG-HEMT achieves a high breakdown voltage and low on-resistance simultaneously. Compared with the conventional device, the HG-HEMT is shown to deliver comparable breakdown voltage while featuring 62% lower on-resistance. [ABSTRACT FROM AUTHOR]

Normally-off operation AlGaN/GaN high electron mobility transistors have been developed utilising a fluorine-based treatment technique combined with a metal-oxide-semiconductor gate architecture. Threshold voltage as high as 5.1 V was achieved by using an 16 nm-thick Al2O3 gate oxide film. Additionally, the device performed a drain current density of 500 mA/mm and a peak transconductance of 100 mS/mm, which are comparable to the conventional normally-on devices. [ABSTRACT FROM AUTHOR]