CHOKING OF ELECTRON FLOW - A MECHANISM OF CURRENT SATURATION IN FIELD-EFFECT TRANSISTORS

We describe a mechanism of the current saturation in a field-effect transistor (FET) caused by choking of electron flow. The choking occurs when the electron velocity at the drain side of the channel reaches the plasma-wave velocity. This effect is quite similar to the choking of a gas flow in a pipe. This mechanism is an alternative to the well-known mechanism of current saturation caused by the drift velocity saturation in the FET channel. We show that the choking mechanism may dominate in a submicrometer AlxGa1-xAs/GaAs FET at 10 K and low drain and gate bias voltages. © 1995 The American Physical Society.