Internal barriers in GaAs epitaxial layers produced by delta-doped dipoles

Abstract

Using a closely spaced pair of δ‐doped layers, one n‐ and one p‐type, at a semiconductor homojunction with different isotype doping densities on each side of the junction, controlled internal Schottky‐type barriers may be produced. We have studied such prototype GaAs diodes with Be and Si δ doping. Good agreement has been obtained between the experimentally determined barrier and that from a self‐consistent Poisson calculation of the zero bias band profile. The temperature dependence of the I–V characteristics has been measured in detail. The results are consistent with the weak temperature dependence of barrier height predicted by the theoretical model. The value of the Richardson constant was also calculated. It has been found that in general the current transport behavior is close to the thermonic limit. A preliminary study of the thermal stability of such diodes has also been carried out.