Publications Repository - Gdańsk University of Technology

Dynamic properties of the MOS transistor under small-signal excitation are determined by kinetic parameters of the carriers injected into the channel, i.e., the low-field mobility, velocity saturation, mobility at the quiescent-point (Q-point), longitudinal electric field in the channel, by dynamic properties of the channel, as well as by an electrical coupling between the perturbed carrier concentration in the channel and the gate and body. The above-mentioned phenomena are essential for a non-quasi-static (NQS) approach to modeling of the MOSFET, which is extremely important when the MOS transistor operates near or above the cut-off frequency fT. The purpose of this work is to present some important results of a new quasi 2D non-quasi-static small-signal four-terminal model of the MOSFET which is based on the results of [1], [2], where, respectively, a quasi 2D representation of the channel is defined and basic equations for the time-dependent quasi-two-space-dimensional non-quasi-static small-signal MOSFET model are derived from first principles. Considerations presented here are performed for a p-channel MOS transistor. In Section 2, a preliminary time-domain analysis of the transistor is carried out. Three fundamental equations, namely, Poisson’s equation for the quasi 2D representation of the transistor, continuity equation, and current transport equation for carriers in the channel are presented in Section 3. Small-signal terminal currents are defined in Section 4. Section 5 provides a validation of the model and concluding remarks.

Authors

• dr hab. inż. Wiesław Kordalski link open in new tab