Schottky barrier diode embedded AlGaN/GaN switching transistor

Abstract

We developed a Schottky barrier diode (SBD) embedded AlGaN/GaN switching transistor to allow negative current flow during off-state condition. An SBD was embedded in a recessed normally-off AlGaN/GaN-on-Si metal-oxide-semiconductor heterostructure field-effect transistor (MOSHFET). The fabricated device exhibited normally-off characteristics with a gate threshold voltage of 2.8 V, a diode turn-on voltage of 1.2 V, and a breakdown voltage of 849 V for the anode-to-drain distance of 8 μm. An on-resistance of 2.66 m cm 2 was achieved at a gate voltage of 16 V in the forward transistor mode. Eliminating the need for an external diode, the SBD embedded switching transistor has advantages of significant reduction in parasitic inductance and chip area.

Diode Embedded AlGaN/GaN Heterojuction Field-Effect Transistor

“…3 along with the forward breakdown characteristics. The measured gate threshold voltage for the forward FET mode was 2.8 V and the reverse turn-on voltage in the freewheeling mode was 1.2 V. The gate threshold voltage depends on the MOS gate whereas the reverse turn-on voltage depends on the Schottky barrier height of the anode contact [8]. The breakdown voltage is governed by the distance between anode and drain.…”

“…2, a Schottky contact electrode is inserted between the source and drain electrodes, being connected electrically to the source electrode. When a positive drain voltage is applied, the Schottky anode is reverse-biased and thus no current flows through the anode whereas the FET mode is in normal operation [8].…”

Monolithically integrated power circuits in high‐voltage GaN‐on‐Si heterojunction technology

“…In [23, 24], a continuously shaped Schottky contact is attached along the channel to the source connected field plate in front of the gate, as shown in the cross‐section in Fig. 10.…”

Normally‐off AlGaN/GaN‐on‐Si MOS‐HFET with a monolithically integrated single‐stage inverter as a gate driver

“…When Si-based gate drivers are used to control GaN power devices, parasitic inductance caused by interconnection and/or external wiring between Si gate driver and GaN power device will cause ringing and voltage spike problems. This, in turn, will reduce the safety operation area and increase the switching loss [7].…”