Heterojunction and schottky barrier ebs targets

Abstract

A metal semiconductor field effect transistor (MESFET) has a Schottky barrier gate formed by depositing an electron transparent electrode to allow its modulation by electric fields and electron beams. The electrode is coupled to an electric field source which is maintained constant or is varied for changing the current flow between the source electrode and drain electrode. An impinging modulating electron beam is directed through the transparent gate to further modulate the current flow between the source electrode and drain electrode and to effect an overall gain in the neighborhood of 10.sup.6. The accelerating potential of the electron beams is of at least an order of magnitude less than conventional cathode ray tube potentials to reduce the possibility of damage to the MESFET material and, since a number of the MESFETS can be modulated by one or more electron beams, they have wide frequency selectivities, broad bandwidths and high switching time capabilities. In addition to an apparatus, a method of improving the modulation of an emerging family of MESFETS first calls for the impressing of an electric field on an electron transparent gate electrode to change the current flow between the source electrode and the drain electrode. This electric field can be a constant value so that a subsequent directing of modulating electrons through the electron transparent gate electrode and into the semiconductor further modulates the current flow between the source electrode and the drain electrode to provide for increased operational capabilities.