Characterization of Very Shallow States in Cryogenic MOSFETs by Wideband Noise Spectroscopy

Temperature ()-dependent MOSFET noise is studied by using a custom-built broadband measurement system.Several n-and p-MOSFETs fabricated by technology nodes of 130 nm, 65 nm, and 22 nm are characterized.Wideband (20 kHz-500 MHz) noise spectroscopy clearly reveals that high- (> 100 K) random telegraph noise (RTN), originating from relatively deep states, varies from device to device, whereas the low- (< 30 K) counterpart exhibits much weaker variability and originates from very shallow states.Variable- - measurements of MOSFETs and p-n junction diodes suggest that these shallow states could emerge throughout the bulk Si at low-.