Flicker Noise (1/f) in 45-nm PDSOI N-Channel FETs at Cryogenic Temperatures for Quantum Computing Applications

In this paper, we have investigated the flicker noise (1/
$f$
) in 45-nm RFSOI NFETs for quantum computing applications. 1/
$f$
noise characterization and analysis were performed in linear region at cryogenic temperatures down to 10K. A Lorentzian-like noise is also observed depending on bias conditions, possibly due to the floating body of PDSOI. The extracted frequency exponent
$(\gamma)$
shows an inverted U-shape behavior with temperature mainly attributed to non-uniform energy distribution of traps in the gate dielectric. The dominant source of 1/
$f$
noise is carrier number fluctuation. Thermal-activation behavior of 1/
$f$
noise is studied, which shows the traps responsible for noise are not thermally activated. Volume trap densities are also extracted from 300K down to 10K. The volume trap density increases with a decrease in temperature, but no significant increase in normalized noise is observed at cryogenic temperatures in the measured NFETs. The non-uniform distribution along with the thermal inactive behavior of traps over the studied temperature range is expected to be a plausible reason for the temperature-independent behavior of normalized noise.