LOW-TEMPERATURE-GROWN GAAS TUNNEL-JUNCTIONS

A GaAs tunnel junction is formed by molecular beam epitaxy at low subs trate temperatures to incorporate excess arsenic, followed by an annea l to precipitate the excess arsenic. This tunnel junction is comparabl e in resistance and peak current density to tunnel junctions grown sto ichiometrically. Owing to the inhomogeneity in this two-phase tunnel j unction, there is only a slight indication of a current peak. This lac k of a valley in the tunnelling characteristic results in a low voltag e drop even for currents in excess of the peak current.