Threshold voltage in FD-SOI MOSFETs

The threshold voltage definition and measurement in ultrathin FD-SOI MOS transistors are revisited by comparing theoretical and pragmatic extraction techniques, including novel approaches. The respective merits and limitations of methods based on the monitoring of the potential, mobile charge, gate-to-channel capacitance and drain current are emphasized. Back-gate biasing, thickness-induced quantization, potential fluctuations and surface roughness can enhance the disparity between various extraction methods. The origin of these deviations is clarified.