STATIC CHARACTERISTICS OF GATE-ALL-AROUND SOI MOSFETS AT CRYOGENIC TEMPERATURES

The operation of so-called gate-all-around (GAA) dual-gate silicon-on- insulator (SOI) MOSFETs at cryogenic temperatures (77 K and 4.2 K) is discussed. It is shown that the transconductance increases by a factor of two upon cooling to 77 K, both for the subthreshold edge conductio n and for the inversion channel. Therefore, the performance improvemen t of the GAA structures over conventional SOI, or bulk MOSFETs is main tained down to liquid helium temperatures. Furthermore, the n-channel devices show negligible hysteresis and kink even at 4.2 K. Metastable behaviour is only observed after the application of a proper bias step to the back-gate electrode.