1. HEMT field effect structures

1.1 Description of a HEMT component

Field-effect transistors are unipolar. The only carriers are usually electrons, as they offer greater mobility than holes. The principle of this component is based on the existence of a conductive channel whose conductance can be modulated by applying an electric field perpendicular to the current direction.

A field-effect transistor (figure 1 ) consists of an n-type semiconductor parallelepiped and three metal contacts: two ohmic contacts to establish an electrical connection with the channel, and a Schottky contact to establish the control. The denomination of the ohmic contacts is defined in relation to the direction...