The development of high-performance quantum computers requires readout systems capable of energy-efficient amplification with minimal noise at cryogenic temperatures. Low-noise amplifiers (LNAs) based on InGaAs high-electron-mobility transistors (InGaAs HEMTs) are commonly employed to read low-power signals from a quantum processor, achieving a noise temperature of 2–4K and a DC power consumption of a few milliwatts. As future quantum computers scale up the number of qubits, the number of required LNAs may increase, potentially limiting power dissipation due to constrained cooling power. Optimizing Ohmic contact to reduce access resistance is crucial for minimizing signal loss, enhancing device efficiency, and reducing power dissipation at cryogenic temperatures.