Quantum mechanics

Voltage

Engineering

Wide-bandgap semiconductor

Materials science

Layer (electronics)

Noise figure

High-electron-mobility transistor

Gallium nitride

Amplifier

Computer science

Transistor

Physics

Nanotechnology

Image (mathematics)

Electronic engineering

Artificial intelligence

Channel (broadcasting)

Topology (electrical circuits)

Noise (video)

CMOS

Optoelectronics

Electrical engineering

IEEE Electron Device Letters

We report scaled, graded-channel AlGaN/GaN HEMTs with an extrinsic f T and f MAX of 170 GHz and 363 GHz, which is the highest in emerging graded-channel GaN HEMTs. At 50-nm gate length, the f T ·Lg of 8.5 GHz·μm is comparable to that of conventional scaled AlGaN/GaN HEMTs fabricated together. At low DC power, the scaled graded-channel AlGaN/GaN HEMTs show a higher f MAX than the scaled AlGaN/GaN HEMT with the same gate length. The devices also exhibit a 2 dB improvement in gain at low DC bias, and the measured minimum noise figure was as low as 0.5 dB at 30 GHz. This is comparable to state-of-the-art device noise figure from a 20-nm gate length AlGaN/GaN HEMT. The combination of improved f T , f MAX , and minimum noise figure at low DC power for the graded-channelAlGaN/GaN HEMTs shows great promise for ultra-low-power, low-noise amplifiers.

360 GHz fMAX Graded-Channel AlGaN/GaN HEMTs for mmW Low-Noise Applications