TRANSIENT-BEHAVIOR OF THE KINK EFFECT IN PARTIALLY-DEPLETED SOI MOSFETS

The behavior of transients in the drain current of partially-depleted (PD) SOI MOSFET's down to L(eff) = 0.2 mu m is examined as a function of drain bias, gate pulses of varying magnitude (V-GS), pulse duration , and pulse frequency, At fixed V-DS, the gate is pulsed to values ran ging from 0.1 V above V-T to V-GS = V-DS. A slow transient is seen whe n the drain is biased at a V-DS where the current kink is observable, This slow transient can be on the order of microseconds depending on t he relative magnitude of the impact ionization rate, For short times a fter the pulse edge or for very short pulses at low frequencies, it is shown that the subthreshold drain current value can be very different from the corresponding de, and that the kink characteristic of PD MOS FET's disappears, However, the kink values can be approached when the pulse frequency and/or duration applied to the gate is increased, due to the latent charge maintained in the floating body at higher frequen cies, No transient current effects were observed in fully-depleted SOI MOSFET's.