10-W/mm AlGaN-GaN HFET with a field modulating plate

TLDR

AlGaN‑GaN heterojunction field‑effect transistors with a field‑modulating plate were fabricated on an SiC substrate. The FP electrode raised the gate‑drain breakdown voltage to 160 V, enabled a 750 mA/mm drain current with negligible collapse, and in a 1‑mm‑wide device produced 10.3 W output power, 18 dB gain, 47.3 % PAE at 2 GHz, achieving the highest 10.3 W/mm power density reported for that gate size.

Abstract

AlGaN-GaN heterojunction field-effect transistors (HFETs) with a field modulating plate (FP) were fabricated on an SiC substrate. The gate-drain breakdown voltage (BV/sub gd/) was significantly improved by employing an FP electrode, and the highest BV/sub gd/ of 160 V was obtained with an FP length (L/sub FP/) of 1 μm. The maximum drain current achieved was 750 mA/mm, together with negligibly small current collapse. A 1-mm-wide FP-FET (L/sub FP/=1 μm) biased at a drain voltage of 65 V demonstrated a continuous wave saturated output power of 10.3 W with a linear gain of 18.0 dB and a power-added efficiency of 47.3% at 2 GHz. To our knowledge, the power density of 10.3 W/mm is the highest ever achieved for any FET of the same gate size.