From Transistors to Circuit Realization of a 50mK Analog Amplifier in FDSOI Technology For Measuring Quantum-Dots

On-chip cryogenic electronics will accelerate the development of silicon-based quantum bits for quantum computing allowing for faster systematic device tests with various materials and geometries. Low-frequency analog characteristics of single FDSOI 28nm MOSFETs and available passive elements were investigated at cryogenic temperature and compared to actual model predictions. The impact on circuit-specifications was studied for a transimpedance amplifier (TIA) operating down to 50mK such as the low- temperature increase of the transistor transconductance leading to a times-5 improvement of the bandwidth. This cryogenic TIA was cointegrated with a quantum dot and compared to a commonly used room-temperature measurement method. Finally, we foresee that the bandwidth of 2.6 kHz can be increased by almost two orders of magnitude while maintaining a 1 μW power consumption, compatible with available cooling power at 100 mK.