Body charge related transient effects in floating body SOI NMOSFETs

The transient operation of submicrometer floating body SOI NMOSFETs is studied and measured down to a nanosecond time scale. We emphasize the role of the overall hole charge in the body of the device, for a global understanding of the transient phenomena: drain current overshoot or undershoot, memory effect, dynamic instabilities... . This charge integrates the device history, with a strongly bias dependent time constant, and influences the drain current, mainly by electrostatic action. The resulting transient current instability has to be considered to avoid anomalous circuit operation.