Single pulse output of partially depleted SOI FETs

Summary form only given. The floating body of partially depleted SOI FETs leads to variation of the threshold voltage, which, in turn, gives rise to variations of drain current depending on bias conditions and device history. This is apparent in the kink effect in I/sub D/-V/sub D/ output curves, and in various reports of transient effects. It has recently been shown that measured I-V curves are history dependent. Thus, for accurate circuit simulation, the history of the partially depleted SOI FET must somehow be taken into account. A method has been developed by which it is possible to measure drain currents, and full I-V curves, for single pulses. Using this technique, it is possible to obtain the device characteristics of any one of a series of pulses, thus accounting for the effect of the prior activity of a device on its output. The method is an extension of the technique which was previously developed for measuring I-V curves without self-heating. The basis of the technique is to apply a short pulse to the gate of the FET, measure the resulting voltage drop at the oscilloscope, and construct an I-V curve from a 50 ohm loadline. This measurement eliminates self-heating because of the short pulse length and low duty cycle. In the case of partially depleted FETs, this measurement method shows that I-V curves also depend on the period between pulses.