InAlN/GaN MISHEMTs With 120 nm T-Shape Recessed Gates on Silicon With Excellent mm-Wave Noise Performance

InAlN/GaN metal-insulator-semiconductor high electron mobility transistors (MISHEMTs) with a 120 nm T-gate and gate recess on a silicon substrate were fabricated. A thin 1.5 nm HfO₂was prepared by plasma-enhanced atomic layer (PEALD) deposition as the gate dielectric. The high electron mobility transistors (HEMTs) exhibited a maximum drain current (Idmax) of 1.5 A/mm, a peak transconductance (gₘₘₐₓ) of 495 mS/mm, a cut-off frequency (fT) of 95 GHz, and a maximum oscillation frequency (fₘₐₓ) of 115 GHz. The fabricated MISHEMTs exhibited a minimum noise figure (NFₘᵢₙ) of 1.3 dB with an associated gain (Gₐ) of 7.7 dB at 30 GHz, and NFₘᵢₙof 1.7 dB andGₐof 6 dB at 40 GHz. These excellent results show the great potential of the InAlN/GaN-on-Si HEMTs in the application of millimeter wave (mm-Wave) low noise amplifiers (LNAs).