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

Abstract

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 $(L_{G}) \leq100$ 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.

Keywords

• Cryogenic
• FDSOI
• band-to-band tunneling