Inability of Single Carrier Tunneling Barriers to Give Subthermal Subthreshold Swings in MOSFETs

A simple potential mapping is used to show that tunneling through a single barrier, as in Schottky-barrier tunneling or source-to-drain tunneling in MOSFETs, cannot give rise to subthreshold swings below the thermionic limit (60 mV/decade at room temperature). While cognizant of the difficulty of proving a negative, it is thus highly unlikely that Schottky-barrier tunneling alone can result in reported instances of subthreshold swings that are less than 60 mV/decade.