Investigation of Noise Performance in InP HEMTs with Varying Indium Channel Composition from 80 K to 300 K

Other conference contribution, 2024

InP High Electron Mobility Transistors (HEMTs) find extensive application in low-noise amplifiers operating within microwave and millimeter-wave frequencies from cryogenic temperature to room temperature. The alloy composition of the InGaAs channel is well known to be a critical factor influencing InP HEMT noise performance. However, a comprehensive understanding of the noise contributions for different channel composition is still lacking. In this study, the noise characteristics of InP HEMTs with indium channel contents of 53%, 60%, 65%, and 70% were measured on-wafer across a temperature range from 80 K to 300 K. The drain voltage and current were kept constant at 0.5 V and 5 mA, respectively. InP HEMT channel noise was extracted using a small-signal model and Pospieszalski’s noise model. A physical interpretation of the total channel noise enabled us to distinguish between thermal noise and excess noise contributions. The analysis revealed that the thermal noise contribution for all InP HEMTs increased with temperature, ranging from 20% to over 60% of the total channel noise. While the 70% indium channel HEMT showed the highest thermal noise, the 53% indium channel HEMT exhibited the lowest thermal noise. In contrast, excess noise remained relatively constant with temperature for all InP HEMT channels. As a result, the 60% indium channel HEMT exhibited the best noise performance among the investigated devices. This is explained by a combination of its comparatively low thermal noise and minimal excess noise in the entire temperature range.