High-Frequency Microwave Noise Characteristics of InAlN/GaN High-Electron Mobility Transistors on Si (111) Substrate

We report for the first time high-frequency microwave noise performance on 0.17-μm T-gate In
_0.17
Al
_0.83
N/GaN high-electron mobility transistors (HEMTs) fabricated on Si(111). The HEMTs exhibited a maximum drain current density of 1320 mA/mm, a maximum extrinsic transconductance of 363 mS/mm, an unity current gain cutoff frequency (f
_T
) of 64 GHz and, a maximum oscillation frequency [fmax
^(U)/
f
_max
(MSG)] of 72/106 GHz. The product f
_max
(U) × L
_g
=12.24 GHz· μm is the highest value ever reported for InAlN/GaN HEMTs on Si substrate. At V
_d
=4 V and V
_g
=-2.25 V, the device exhibited a minimum noise figure (NF
_min
) of 1.16 dB for 10 GHz and 1.76 dB for 18 GHz. Small variation of NF
_min
(<;0.5 dB) from 8% to 48% with I
_Dmax
(100-636 mA/mm) was observed.