Temperature Dependent Variations of Low-Frequency Noise Sources in Cryogenic Short-Channel Bulk MOSFETs

This study investigated changes in low-frequency noise sources associated with short-channel bulk metal-oxide-semiconductor field-effect transistors (MOSFETs) by analyzing random telegraph noise (RTN) from 300 K down to 3 K. The power spectral density (PSD) of the drain current, which exhibited RTN characteristics in the frequency domain, changed with temperature. In addition, the effect of temperature on the PSD was not monotonic such that peaks were generated at specific temperatures. A comparison between p-type and n-type MOSFETs established that the former exhibited PSD values nearly an order of magnitude smaller than those of the latter. The PSD peaks observed in the temperature domain were analyzed using a theory based on the Shockley-Read-Hall model and the energy levels of the charge traps responsible for RTN were determined. Assessing the temperatures and corresponding energy levels associated with these PSD peaks showed a trend in which energy levels approached band edges as the temperature was decreased. This study assists in the development of strategies to reduce low-frequency noises generated by cryogenic qubit controllers by elucidating the impact of band-tail states on noises at 4 K.