Three Temperature Regimes in Subthreshold Characteristics of FD-SOI pMOSFETs from Room-temperature to Cryogenic Temperatures

We reported three temperature regimes in subthreshold characteristics of 22-nm FD-SOI p-MOSFETs at operation T = 300 K - 4.5 K. Subthreshold swing (SS)-plateau at 125 K - 50 K in combination with SS-linearity at T = 300 K - 125 K and 50 K - 4.5 K were observed in different types of FD-SOI p-MOSFETs with channel length (LG) ≤ 100 nm, which is possibly attributed to temperature-dependent dopant ionization induced band-to-band and trap-assisted tunneling across the drain-body junction. The phenomenon of SS linearly decreasing with temperature at T < 50 K is not observed in neither FD-SOI n-MOSFETs nor 28 nm bulk CMOSFETs.