Anomalous Voltage Overshoot During Turn-Off of Thin-Film n-Channel SOI MOSFET's

This paper reports an anomalous output voltage overshoot observed during the turn-off of single short-channel thin-film silicon-on-insulator (SOI) n-MOSFET's. The parasitic floating-base bipolar device, triggered by impact ionization, is shown to be responsible for this effect. Because switching occurs over a subnanosecond time scale, the charge dynamics related to the bipolar action are essential to explain this voltage overshoot. © 1993 IEEE