0.18 dB Low-Noise Figure at 10 GHz for GaN MIS-HEMT With Plasma-Enhanced Atomic Layer Deposition SiN Layer

Investigation into the noise performance of GaN metal-insulator-semiconductor HEMT with 5-nm SiN dielectric layer has been performed in this work. The fabricated MIS-HEMT exhibits a minimum noise figure ( $NF_{\text {min}}{)}$ of 0.18 dB at 10 GHz and 0.45 dB at 18 GHz with a 10 V drain voltage and ~70 mA/mm drain current, which is considerably smaller than the corresponding values (1.0 dB and 1.9 dB respectively) obtained for the controlled HEMT. A corrected physical base noise model has been conducted to evaluate the improvement. The influence of the suppressed gate leakage current and reduced channel resistance on NF _min is stronger than that of the parasitic capacitance, which finally contributes to a decreased NF _min for MIS-HEMT. Moreover, the dependences of noise characteristics on the bias voltages are also monitored, achieving a tiny $NF_{\text {min}} < 0.8$ dB at 18 GHz with a 20 V drain bias. These findings sufficiently reveal the potential of GaN MIS-HEMT utilizing in low-noise amplifiers.