The experimental results of the cryogenic temperature characteristics on 0.18- m silicon-on-insulator (SOI) metaloxide-silicon (MOS) field-effect-transistors (FETs) were presented in detail. The current and capacitance characteristics for different operating conditions ranging from 300 K to 10 K were discussed. SOI MOSFETs at cryogenic temperature exhibit improved performance, as expected. Nevertheless, operation at cryogenic temperature also demonstrates abnormal behaviors, such as the impur···