NEW TRANSPORT PHENOMENA IN A BALLISTIC HETEROSTRUCTURE FIELD-EFFECT TRANSISTOR

We observed new transport properties in an InGaAs/InAlAs field-effect transistor with source-drain separation of approximately 40 nm. Throug h measurements of real-space transfer current to the gate we obtained clear evidence of ballistic electron transport in the two-dimensional channel of the device. Another important new feature is the drain curr ent saturation at low drain biases. This effect is explained by a poor electron exchange at the interface of a two-dimensional gas with bulk at the device contacts.