AN INVESTIGATION OF THE PROPERTIES OF INTIMATE IN-INXGA1-XAS(100) INTERFACES FORMED AT ROOM AND CRYOGENIC TEMPERATURES

The electrical, chemical and structural properties of the interfaces f ormed at room and low temperatures, between In and atomically clean In 53Ga47As/InP(100) have been studied. Current-voltage measurements indi cate that diodes formed at 80 K exhibit significantly higher Schottky barriers (phi(b) = 0.45 eV) than diodes formed at 294 K (phi(b) = 0.30 eV). The reactions occurring during the formation of In-In53Ga47As/In P(100) interfaces at room and low temperatures have been investigated using Soft X-Ray photoemission spectroscopy. Our results show that met allisation at room temperature results in a predominantly three dimens ional mode of growth, accompanied by the out-diffusion of As. Low temp erature (125 K) metallisation appears to reduce clustering and inhibit As out-diffusion. Examination of the resulting interfaces by transmis sion electron microscopy confirms the more uniform nature of the metal layers formed at low temperature. These observations, in conjunction with the barrier heights measured by the I-V technique, are discussed in the context of currently supported models of Schottky barrier forma tion. (C) 1998 Elsevier Science B.V.