A High-Power GaN-Based Field-Effect Transistor for Large-Current Operation

Abstract

A high power AlGaN/GaN hetero field-effect transistor (HFET) for large-current operation was fabricated. An Al0.2Ga0.8N/GaN heterostructure was grown using gas-source molecular-beam epitaxy (GSMBE). The mobility of Al0.2Ga0.8N/GaN was about 1200 cm2/Vs at room temperature. The structure of a HFET for the large-current operation was composed of 400 units of FET. The gate width and length of a unit FET were 500 μm and 2 μm, respectively. The total gate width was 20 cm. We confirmed that an AlGaN/GaN HFET was also operated under current conditions above 15 A. The on-resistance of the HFET was 3 mΩ cm2. This is a lower value of GaN based FET. The Schottky breakdown voltage of the gate and source was 600 V. An undoped GaN layer had a high breakdown voltage above 1100 V. It was thus demonstrated that a GaN-based FET can be used for power devices.