METAL-SEMICONDUCTOR INTERFACIAL REACTIONS

Vapor phase deposition of thin metal films on semiconductors followed by annealing frequently leads to the nucleation and growth of one or more reaction products in the vicinity of the metal/semiconductor interface. Often, these products are intermetallic compounds that may be distributed as precipitates in the interfacial region. The composition, size, shape, and areal density of these precipitates may be the major factors in determining the electrical properties of the interface. The semiconductors studied were GaAs, SiC, and semiconducting diamond, while the metals were principally the refractory metals, although several other metals were also investigated. The interfaces of representative samples were examined using Auger electron spectroscopy (AES), secondary ion mass spectroscopy (SIMS), X-ray diffraction (XRD), Rutherford backscattering spectroscopy (RBS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), including selected area electron diffraction (SAD), and optical metallography. The electrical properties were evaluated by current-potential (I-V) and Hall effect measurements.