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 In0.17Al0.83N/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 (fT) of 64 GHz and, a maximum oscillation frequency [fmax(U)/fmax(MSG)] of 72/106 GHz. The product fmax(U) × Lg=12.24 GHz· μm is the highest value ever reported for InAlN/GaN HEMTs on Si substrate. At Vd=4 V and Vg=-2.25 V, the device exhibited a minimum noise figure (NFmin) of 1.16 dB for 10 GHz and 1.76 dB for 18 GHz. Small variation of NFmin(Dmax(100-636 mA/mm) was observed.