Record-low subthreshold Swing Below 5 mV/dec at 4 K in planar Bulk InGaAs MOSFETs: A breakthrough for low-power, low-noise cryogenic electronics in Scalable Quantum Computing

The rapid advancements in scalable quantum computing are driving the need for cryogenic electronics with low power consumption and minimal noise. While InP HEMTs and Si MOSFETs are presently used as cryogenic electronics for quantum computing, InGaAs MOSFETs offer a compelling alternative, combining high electron mobility with low gate leakage. Subthreshold swing (SS) is a crucial parameter, as it directly affects power consumption and noise performance, especially at cryogenic temperatures of 4 K and below, where devices operate near the subthreshold region to minimize power. Achieving low SS is essential for cryogenic electronics in scalable quantum computing.

Our planar bulk InGaAs MOSFETs, passivated with in situ deposited gate dielectrics, exhibit significantly reduced SS values of approximately 85 mV/dec at 300 K, outperforming other planar bulk InGaAs MOSFETs using ex situ oxide deposition. Notably, the SS decreases to below 5 mV/dec at 4 K, which are record-low values among state-of-the-art InGaAs MOSFETs, InP HEMTs, and Si MOSFETs, even when compared to advanced designs like ultra-thin body or low channel doping structures typically aimed at reducing SS. Our results highlight the strong potential of planar bulk InGaAs MOSFETs with in situ deposited oxides as a promising technology for low power consumption, high power-to-gain efficiency, and low noise cryogenic electronics, crucial for scalable quantum computing.